Interior-Exterior Thermometer
01-15-2006, 11:57 AM
#61
Guest
Posts: n/a
Re: Interior-Exterior Thermometer
I think what it comes down to is there is really no good place if you want a
true air temperature.
Anywhere on/underneath the vehicle will be influenced by heat radiation from
the roadway. Fresh blacktop in the summer sun will be much hotter and even
in the winter the sun will make the roadway warmer than the air just a bit
off the road.
"Lee Ayrton" <layrton@panix.com> wrote in message
news:dqdqhj$n1$1@reader2.panix.com...
> I'd guess that the "car wash" warning had more to do with it not getting
> broomed off by the RoboWash brushes.
>
> There can be a fair bit of difference in temperature with just a few feet
> of elevation change, and the air can be a good deal warmer than the
> surface you're driving on and it can make a difference -- 33F vs. 31F. If
> I were using it as an icing indicator I'd want it down by the pavement
> surface.
>
> Tomes wrote:
>> It's just that on the packaging it noted to keep the sensor out of the
>> 'way
>> of the car wash' or somesuch; it looks sealed enough though. Maybe the
>> peril is that it falls off under water pressure spray, not that it will
>> leak. Would the temperature be much different at these two elevations
>> you
>> think? This one audibly alarms at 32 degrees too for the black ice
>> alert.
>> Tomes
>>
>> "Mike Romain" <romainm@sympatico.ca> wrote in message
>> news:43C98DDC.5F17AE2@sympatico.ca...
>>
>>>The one in our old Volvo was below the front bumper to pick up the road
>>>temperature. It went red at 32 to let you know to watch for black ice.
>>>
>>>Mike
>>>86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>>88 Cherokee 235 BFG AT's
>>>Canadian Off Road Trips Photos: Non members can still view!
>>>Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>>(More Off Road album links at bottom of the view page)
>>>
>>>Tomes wrote:
>>>
>>>>Thanks Jeff. Right now I am running it under the carpet, out the back
>>
>> door
>>
>>>>and mounting it on the bottom of the 3rd brake light. We will see how
>>
>> that
>>
>>>>works out. It is in the elements and somewhat protected.
>>>>Tomes
>>>>
>>>>"Jeff Strickland" <crwlr@yahoo.com> wrote in message
>>>>news:vdidndNoI_1l9VTenZ2dnUVZ_tydnZ2d@ez2.net. ..
>>>>
>>>>>On my BMW, the probe is mounted in one of the aor ducts that direct
>>
>> cold
>>
>>>>air
>>>>
>>>>>onto the brake rotors.
>>>>>
>>>>>All you need to do is put it where it won't be affected by the hot
>>
>> exhaust
>>
>>>>>system. Surely the probe is adequately sealed to deal with water
>>
>> splashing
>>
>>>>>on it. I'd pick a spot where the rocks won't get it, if there is such
>>
>> a
>>
>>>>spot
>>>>
>>>>>...
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>"Tomes" <askme@here.net> wrote in message
>>>>>news:2C0xf.5343$ZA2.3845@newsread1.news.atl.e arthlink.net...
>>>>>
>>>>>>Hi folks,
>>>>>>One of the things I got for Christmas in a clock/temperature monitor
>>>>
>>>>that
>>>>
>>>>>>tells you what the temperature inside the Jeep is and also what
>>>>>>temperature
>>>>>>is outside the jeep. It sticks with sticky velcro anywhere you want
>>
>> to
>>
>>>>>>stick it - I put mine over the glove box so my daughter has
>>
>> something to
>>
>>>>>>do
>>>>>><grin>. My question for the folks is this:
>>>>>>
>>>>>>It comes with a lead on a long wire for the outside temp sensor and
>>
>> I am
>>
>>>>>>having an indecisive time coming up with a spot to stick it. The
>>>>>>literature
>>>>>>(the deep thought stuff on the packaging) suggests in the door
>>
>> frame,
>>
>>>>but
>>>>
>>>>>>on
>>>>>>this Jeep the doors are off most of the summer as much as I can get
>>
>> away
>>
>>>>>>with. The idea here is it beeps when freezing to warn for black ice
>>>>>>possibility. It needs to stay relatively dry and not be affected by
>>>>
>>>>motor
>>>>
>>>>>>heat. It has maybe 8 feet of wire. Suggestions?
>>>>>>Thanks folks,
>>>>>>Tomes
>>>>>>02 TJ
>>>>>>
>>>>>>
>>>>>
>>
true air temperature.
Anywhere on/underneath the vehicle will be influenced by heat radiation from
the roadway. Fresh blacktop in the summer sun will be much hotter and even
in the winter the sun will make the roadway warmer than the air just a bit
off the road.
"Lee Ayrton" <layrton@panix.com> wrote in message
news:dqdqhj$n1$1@reader2.panix.com...
> I'd guess that the "car wash" warning had more to do with it not getting
> broomed off by the RoboWash brushes.
>
> There can be a fair bit of difference in temperature with just a few feet
> of elevation change, and the air can be a good deal warmer than the
> surface you're driving on and it can make a difference -- 33F vs. 31F. If
> I were using it as an icing indicator I'd want it down by the pavement
> surface.
>
> Tomes wrote:
>> It's just that on the packaging it noted to keep the sensor out of the
>> 'way
>> of the car wash' or somesuch; it looks sealed enough though. Maybe the
>> peril is that it falls off under water pressure spray, not that it will
>> leak. Would the temperature be much different at these two elevations
>> you
>> think? This one audibly alarms at 32 degrees too for the black ice
>> alert.
>> Tomes
>>
>> "Mike Romain" <romainm@sympatico.ca> wrote in message
>> news:43C98DDC.5F17AE2@sympatico.ca...
>>
>>>The one in our old Volvo was below the front bumper to pick up the road
>>>temperature. It went red at 32 to let you know to watch for black ice.
>>>
>>>Mike
>>>86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>>88 Cherokee 235 BFG AT's
>>>Canadian Off Road Trips Photos: Non members can still view!
>>>Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>>(More Off Road album links at bottom of the view page)
>>>
>>>Tomes wrote:
>>>
>>>>Thanks Jeff. Right now I am running it under the carpet, out the back
>>
>> door
>>
>>>>and mounting it on the bottom of the 3rd brake light. We will see how
>>
>> that
>>
>>>>works out. It is in the elements and somewhat protected.
>>>>Tomes
>>>>
>>>>"Jeff Strickland" <crwlr@yahoo.com> wrote in message
>>>>news:vdidndNoI_1l9VTenZ2dnUVZ_tydnZ2d@ez2.net. ..
>>>>
>>>>>On my BMW, the probe is mounted in one of the aor ducts that direct
>>
>> cold
>>
>>>>air
>>>>
>>>>>onto the brake rotors.
>>>>>
>>>>>All you need to do is put it where it won't be affected by the hot
>>
>> exhaust
>>
>>>>>system. Surely the probe is adequately sealed to deal with water
>>
>> splashing
>>
>>>>>on it. I'd pick a spot where the rocks won't get it, if there is such
>>
>> a
>>
>>>>spot
>>>>
>>>>>...
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>"Tomes" <askme@here.net> wrote in message
>>>>>news:2C0xf.5343$ZA2.3845@newsread1.news.atl.e arthlink.net...
>>>>>
>>>>>>Hi folks,
>>>>>>One of the things I got for Christmas in a clock/temperature monitor
>>>>
>>>>that
>>>>
>>>>>>tells you what the temperature inside the Jeep is and also what
>>>>>>temperature
>>>>>>is outside the jeep. It sticks with sticky velcro anywhere you want
>>
>> to
>>
>>>>>>stick it - I put mine over the glove box so my daughter has
>>
>> something to
>>
>>>>>>do
>>>>>><grin>. My question for the folks is this:
>>>>>>
>>>>>>It comes with a lead on a long wire for the outside temp sensor and
>>
>> I am
>>
>>>>>>having an indecisive time coming up with a spot to stick it. The
>>>>>>literature
>>>>>>(the deep thought stuff on the packaging) suggests in the door
>>
>> frame,
>>
>>>>but
>>>>
>>>>>>on
>>>>>>this Jeep the doors are off most of the summer as much as I can get
>>
>> away
>>
>>>>>>with. The idea here is it beeps when freezing to warn for black ice
>>>>>>possibility. It needs to stay relatively dry and not be affected by
>>>>
>>>>motor
>>>>
>>>>>>heat. It has maybe 8 feet of wire. Suggestions?
>>>>>>Thanks folks,
>>>>>>Tomes
>>>>>>02 TJ
>>>>>>
>>>>>>
>>>>>
>>
01-15-2006, 12:22 PM
#62
Guest
Posts: n/a
Re: Interior-Exterior Thermometer
Mike Romain proclaimed:
> The temperature on the road is different than the air temperature. A
> lot of traffic or thawed ground can keep the road surface wet/warm when
> the air temperature is below freezing and a hard frost can keep the road
> frozen when the air temperature has warmed up.
.... or a bridge or other structure that allows chilled air to get under
the roadway. Or coming around a corner at the end of a nice sunlit
stretch of dark pavement onto an area where water has flowed across the
road and frozen on the shady sections--or worse, only the bottom is
frozen and there is free water on top of it. Or the road just changes
color...
>
> Sun also has a 'radical' affect on the surface temperature of a
> vehicle. So does your vehicle's heater. The rear door of our Cherokee
> can be frozen up and the vehicle's heater will eventually warm it up
> enough to melt.
Within reason, the best location is near the front of the vehicle.
Paying attention any time the temp gets within a few yards of freezing
is a driver issue.
I'd sure use a good filling, non-hardening non-water based adhesive and
thoroughly fill any places where the wiring goes thru bodywork, has a
connector, etc.
> The temperature on the road is different than the air temperature. A
> lot of traffic or thawed ground can keep the road surface wet/warm when
> the air temperature is below freezing and a hard frost can keep the road
> frozen when the air temperature has warmed up.
.... or a bridge or other structure that allows chilled air to get under
the roadway. Or coming around a corner at the end of a nice sunlit
stretch of dark pavement onto an area where water has flowed across the
road and frozen on the shady sections--or worse, only the bottom is
frozen and there is free water on top of it. Or the road just changes
color...
>
> Sun also has a 'radical' affect on the surface temperature of a
> vehicle. So does your vehicle's heater. The rear door of our Cherokee
> can be frozen up and the vehicle's heater will eventually warm it up
> enough to melt.
Within reason, the best location is near the front of the vehicle.
Paying attention any time the temp gets within a few yards of freezing
is a driver issue.
I'd sure use a good filling, non-hardening non-water based adhesive and
thoroughly fill any places where the wiring goes thru bodywork, has a
connector, etc.
01-15-2006, 12:22 PM
#63
Guest
Posts: n/a
Re: Interior-Exterior Thermometer
Mike Romain proclaimed:
> The temperature on the road is different than the air temperature. A
> lot of traffic or thawed ground can keep the road surface wet/warm when
> the air temperature is below freezing and a hard frost can keep the road
> frozen when the air temperature has warmed up.
.... or a bridge or other structure that allows chilled air to get under
the roadway. Or coming around a corner at the end of a nice sunlit
stretch of dark pavement onto an area where water has flowed across the
road and frozen on the shady sections--or worse, only the bottom is
frozen and there is free water on top of it. Or the road just changes
color...
>
> Sun also has a 'radical' affect on the surface temperature of a
> vehicle. So does your vehicle's heater. The rear door of our Cherokee
> can be frozen up and the vehicle's heater will eventually warm it up
> enough to melt.
Within reason, the best location is near the front of the vehicle.
Paying attention any time the temp gets within a few yards of freezing
is a driver issue.
I'd sure use a good filling, non-hardening non-water based adhesive and
thoroughly fill any places where the wiring goes thru bodywork, has a
connector, etc.
> The temperature on the road is different than the air temperature. A
> lot of traffic or thawed ground can keep the road surface wet/warm when
> the air temperature is below freezing and a hard frost can keep the road
> frozen when the air temperature has warmed up.
.... or a bridge or other structure that allows chilled air to get under
the roadway. Or coming around a corner at the end of a nice sunlit
stretch of dark pavement onto an area where water has flowed across the
road and frozen on the shady sections--or worse, only the bottom is
frozen and there is free water on top of it. Or the road just changes
color...
>
> Sun also has a 'radical' affect on the surface temperature of a
> vehicle. So does your vehicle's heater. The rear door of our Cherokee
> can be frozen up and the vehicle's heater will eventually warm it up
> enough to melt.
Within reason, the best location is near the front of the vehicle.
Paying attention any time the temp gets within a few yards of freezing
is a driver issue.
I'd sure use a good filling, non-hardening non-water based adhesive and
thoroughly fill any places where the wiring goes thru bodywork, has a
connector, etc.
01-15-2006, 12:22 PM
#64
Guest
Posts: n/a
Re: Interior-Exterior Thermometer
Mike Romain proclaimed:
> The temperature on the road is different than the air temperature. A
> lot of traffic or thawed ground can keep the road surface wet/warm when
> the air temperature is below freezing and a hard frost can keep the road
> frozen when the air temperature has warmed up.
.... or a bridge or other structure that allows chilled air to get under
the roadway. Or coming around a corner at the end of a nice sunlit
stretch of dark pavement onto an area where water has flowed across the
road and frozen on the shady sections--or worse, only the bottom is
frozen and there is free water on top of it. Or the road just changes
color...
>
> Sun also has a 'radical' affect on the surface temperature of a
> vehicle. So does your vehicle's heater. The rear door of our Cherokee
> can be frozen up and the vehicle's heater will eventually warm it up
> enough to melt.
Within reason, the best location is near the front of the vehicle.
Paying attention any time the temp gets within a few yards of freezing
is a driver issue.
I'd sure use a good filling, non-hardening non-water based adhesive and
thoroughly fill any places where the wiring goes thru bodywork, has a
connector, etc.
> The temperature on the road is different than the air temperature. A
> lot of traffic or thawed ground can keep the road surface wet/warm when
> the air temperature is below freezing and a hard frost can keep the road
> frozen when the air temperature has warmed up.
.... or a bridge or other structure that allows chilled air to get under
the roadway. Or coming around a corner at the end of a nice sunlit
stretch of dark pavement onto an area where water has flowed across the
road and frozen on the shady sections--or worse, only the bottom is
frozen and there is free water on top of it. Or the road just changes
color...
>
> Sun also has a 'radical' affect on the surface temperature of a
> vehicle. So does your vehicle's heater. The rear door of our Cherokee
> can be frozen up and the vehicle's heater will eventually warm it up
> enough to melt.
Within reason, the best location is near the front of the vehicle.
Paying attention any time the temp gets within a few yards of freezing
is a driver issue.
I'd sure use a good filling, non-hardening non-water based adhesive and
thoroughly fill any places where the wiring goes thru bodywork, has a
connector, etc.
01-15-2006, 12:27 PM
#65
Guest
Posts: n/a
Re: Interior-Exterior Thermometer
Lee Ayrton proclaimed:
> I'd guess that the "car wash" warning had more to do with it not getting
> broomed off by the RoboWash brushes.
>
> There can be a fair bit of difference in temperature with just a few
> feet of elevation change, and the air can be a good deal warmer than the
> surface you're driving on and it can make a difference -- 33F vs. 31F.
> If I were using it as an icing indicator I'd want it down by the
> pavement surface.
With very few exceptions, the air is always colder than the surface,
even beginning as close as a few centimeters above and or below the
surface. Over solid ground, in all my years measuring these trivia,
even when you think you might, if there was any insolation at all, the
surface would be warmer than air just a few CM above it. Frozen ground
on occasion would be colder, but generally lightly colored with no
insolation. Over areas with canyons and other places where air from
well beneath the roadway can get near the roadway, you are more likely
to run into colder surfaces. If the minor degree difference in mounting
location is taken by the driver as anything significant, that driver is
a sliding accident just waiting to happen. There is more temp
difference along a single mile of typical roadway than any trivia
vertically.
>
> Tomes wrote:
>
>> It's just that on the packaging it noted to keep the sensor out of the
>> 'way
>> of the car wash' or somesuch; it looks sealed enough though. Maybe the
>> peril is that it falls off under water pressure spray, not that it will
>> leak. Would the temperature be much different at these two elevations
>> you
>> think? This one audibly alarms at 32 degrees too for the black ice
>> alert.
>> Tomes
>>
>> "Mike Romain" <romainm@sympatico.ca> wrote in message
>> news:43C98DDC.5F17AE2@sympatico.ca...
>>
>>> The one in our old Volvo was below the front bumper to pick up the road
>>> temperature. It went red at 32 to let you know to watch for black ice.
>>>
>>> Mike
>>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>> 88 Cherokee 235 BFG AT's
>>> Canadian Off Road Trips Photos: Non members can still view!
>>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>> (More Off Road album links at bottom of the view page)
>>>
>>> Tomes wrote:
>>>
>>>> Thanks Jeff. Right now I am running it under the carpet, out the back
>>
>>
>> door
>>
>>>> and mounting it on the bottom of the 3rd brake light. We will see how
>>
>>
>> that
>>
>>>> works out. It is in the elements and somewhat protected.
>>>> Tomes
>>>>
>>>> "Jeff Strickland" <crwlr@yahoo.com> wrote in message
>>>> news:vdidndNoI_1l9VTenZ2dnUVZ_tydnZ2d@ez2.net...
>>>>
>>>>> On my BMW, the probe is mounted in one of the aor ducts that direct
>>
>>
>> cold
>>
>>>> air
>>>>
>>>>> onto the brake rotors.
>>>>>
>>>>> All you need to do is put it where it won't be affected by the hot
>>
>>
>> exhaust
>>
>>>>> system. Surely the probe is adequately sealed to deal with water
>>
>>
>> splashing
>>
>>>>> on it. I'd pick a spot where the rocks won't get it, if there is such
>>
>>
>> a
>>
>>>> spot
>>>>
>>>>> ...
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> "Tomes" <askme@here.net> wrote in message
>>>>> news:2C0xf.5343$ZA2.3845@newsread1.news.atl.earthl ink.net...
>>>>>
>>>>>> Hi folks,
>>>>>> One of the things I got for Christmas in a clock/temperature monitor
>>>>
>>>>
>>>> that
>>>>
>>>>>> tells you what the temperature inside the Jeep is and also what
>>>>>> temperature
>>>>>> is outside the jeep. It sticks with sticky velcro anywhere you want
>>
>>
>> to
>>
>>>>>> stick it - I put mine over the glove box so my daughter has
>>
>>
>> something to
>>
>>>>>> do
>>>>>> <grin>. My question for the folks is this:
>>>>>>
>>>>>> It comes with a lead on a long wire for the outside temp sensor and
>>
>>
>> I am
>>
>>>>>> having an indecisive time coming up with a spot to stick it. The
>>>>>> literature
>>>>>> (the deep thought stuff on the packaging) suggests in the door
>>
>>
>> frame,
>>
>>>> but
>>>>
>>>>>> on
>>>>>> this Jeep the doors are off most of the summer as much as I can get
>>
>>
>> away
>>
>>>>>> with. The idea here is it beeps when freezing to warn for black ice
>>>>>> possibility. It needs to stay relatively dry and not be affected by
>>>>
>>>>
>>>> motor
>>>>
>>>>>> heat. It has maybe 8 feet of wire. Suggestions?
>>>>>> Thanks folks,
>>>>>> Tomes
>>>>>> 02 TJ
>>>>>>
>>>>>>
>>>>>
>>
>>
> I'd guess that the "car wash" warning had more to do with it not getting
> broomed off by the RoboWash brushes.
>
> There can be a fair bit of difference in temperature with just a few
> feet of elevation change, and the air can be a good deal warmer than the
> surface you're driving on and it can make a difference -- 33F vs. 31F.
> If I were using it as an icing indicator I'd want it down by the
> pavement surface.
With very few exceptions, the air is always colder than the surface,
even beginning as close as a few centimeters above and or below the
surface. Over solid ground, in all my years measuring these trivia,
even when you think you might, if there was any insolation at all, the
surface would be warmer than air just a few CM above it. Frozen ground
on occasion would be colder, but generally lightly colored with no
insolation. Over areas with canyons and other places where air from
well beneath the roadway can get near the roadway, you are more likely
to run into colder surfaces. If the minor degree difference in mounting
location is taken by the driver as anything significant, that driver is
a sliding accident just waiting to happen. There is more temp
difference along a single mile of typical roadway than any trivia
vertically.
>
> Tomes wrote:
>
>> It's just that on the packaging it noted to keep the sensor out of the
>> 'way
>> of the car wash' or somesuch; it looks sealed enough though. Maybe the
>> peril is that it falls off under water pressure spray, not that it will
>> leak. Would the temperature be much different at these two elevations
>> you
>> think? This one audibly alarms at 32 degrees too for the black ice
>> alert.
>> Tomes
>>
>> "Mike Romain" <romainm@sympatico.ca> wrote in message
>> news:43C98DDC.5F17AE2@sympatico.ca...
>>
>>> The one in our old Volvo was below the front bumper to pick up the road
>>> temperature. It went red at 32 to let you know to watch for black ice.
>>>
>>> Mike
>>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>> 88 Cherokee 235 BFG AT's
>>> Canadian Off Road Trips Photos: Non members can still view!
>>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>> (More Off Road album links at bottom of the view page)
>>>
>>> Tomes wrote:
>>>
>>>> Thanks Jeff. Right now I am running it under the carpet, out the back
>>
>>
>> door
>>
>>>> and mounting it on the bottom of the 3rd brake light. We will see how
>>
>>
>> that
>>
>>>> works out. It is in the elements and somewhat protected.
>>>> Tomes
>>>>
>>>> "Jeff Strickland" <crwlr@yahoo.com> wrote in message
>>>> news:vdidndNoI_1l9VTenZ2dnUVZ_tydnZ2d@ez2.net...
>>>>
>>>>> On my BMW, the probe is mounted in one of the aor ducts that direct
>>
>>
>> cold
>>
>>>> air
>>>>
>>>>> onto the brake rotors.
>>>>>
>>>>> All you need to do is put it where it won't be affected by the hot
>>
>>
>> exhaust
>>
>>>>> system. Surely the probe is adequately sealed to deal with water
>>
>>
>> splashing
>>
>>>>> on it. I'd pick a spot where the rocks won't get it, if there is such
>>
>>
>> a
>>
>>>> spot
>>>>
>>>>> ...
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> "Tomes" <askme@here.net> wrote in message
>>>>> news:2C0xf.5343$ZA2.3845@newsread1.news.atl.earthl ink.net...
>>>>>
>>>>>> Hi folks,
>>>>>> One of the things I got for Christmas in a clock/temperature monitor
>>>>
>>>>
>>>> that
>>>>
>>>>>> tells you what the temperature inside the Jeep is and also what
>>>>>> temperature
>>>>>> is outside the jeep. It sticks with sticky velcro anywhere you want
>>
>>
>> to
>>
>>>>>> stick it - I put mine over the glove box so my daughter has
>>
>>
>> something to
>>
>>>>>> do
>>>>>> <grin>. My question for the folks is this:
>>>>>>
>>>>>> It comes with a lead on a long wire for the outside temp sensor and
>>
>>
>> I am
>>
>>>>>> having an indecisive time coming up with a spot to stick it. The
>>>>>> literature
>>>>>> (the deep thought stuff on the packaging) suggests in the door
>>
>>
>> frame,
>>
>>>> but
>>>>
>>>>>> on
>>>>>> this Jeep the doors are off most of the summer as much as I can get
>>
>>
>> away
>>
>>>>>> with. The idea here is it beeps when freezing to warn for black ice
>>>>>> possibility. It needs to stay relatively dry and not be affected by
>>>>
>>>>
>>>> motor
>>>>
>>>>>> heat. It has maybe 8 feet of wire. Suggestions?
>>>>>> Thanks folks,
>>>>>> Tomes
>>>>>> 02 TJ
>>>>>>
>>>>>>
>>>>>
>>
>>
01-15-2006, 12:27 PM
#66
Guest
Posts: n/a
Re: Interior-Exterior Thermometer
Lee Ayrton proclaimed:
> I'd guess that the "car wash" warning had more to do with it not getting
> broomed off by the RoboWash brushes.
>
> There can be a fair bit of difference in temperature with just a few
> feet of elevation change, and the air can be a good deal warmer than the
> surface you're driving on and it can make a difference -- 33F vs. 31F.
> If I were using it as an icing indicator I'd want it down by the
> pavement surface.
With very few exceptions, the air is always colder than the surface,
even beginning as close as a few centimeters above and or below the
surface. Over solid ground, in all my years measuring these trivia,
even when you think you might, if there was any insolation at all, the
surface would be warmer than air just a few CM above it. Frozen ground
on occasion would be colder, but generally lightly colored with no
insolation. Over areas with canyons and other places where air from
well beneath the roadway can get near the roadway, you are more likely
to run into colder surfaces. If the minor degree difference in mounting
location is taken by the driver as anything significant, that driver is
a sliding accident just waiting to happen. There is more temp
difference along a single mile of typical roadway than any trivia
vertically.
>
> Tomes wrote:
>
>> It's just that on the packaging it noted to keep the sensor out of the
>> 'way
>> of the car wash' or somesuch; it looks sealed enough though. Maybe the
>> peril is that it falls off under water pressure spray, not that it will
>> leak. Would the temperature be much different at these two elevations
>> you
>> think? This one audibly alarms at 32 degrees too for the black ice
>> alert.
>> Tomes
>>
>> "Mike Romain" <romainm@sympatico.ca> wrote in message
>> news:43C98DDC.5F17AE2@sympatico.ca...
>>
>>> The one in our old Volvo was below the front bumper to pick up the road
>>> temperature. It went red at 32 to let you know to watch for black ice.
>>>
>>> Mike
>>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>> 88 Cherokee 235 BFG AT's
>>> Canadian Off Road Trips Photos: Non members can still view!
>>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>> (More Off Road album links at bottom of the view page)
>>>
>>> Tomes wrote:
>>>
>>>> Thanks Jeff. Right now I am running it under the carpet, out the back
>>
>>
>> door
>>
>>>> and mounting it on the bottom of the 3rd brake light. We will see how
>>
>>
>> that
>>
>>>> works out. It is in the elements and somewhat protected.
>>>> Tomes
>>>>
>>>> "Jeff Strickland" <crwlr@yahoo.com> wrote in message
>>>> news:vdidndNoI_1l9VTenZ2dnUVZ_tydnZ2d@ez2.net...
>>>>
>>>>> On my BMW, the probe is mounted in one of the aor ducts that direct
>>
>>
>> cold
>>
>>>> air
>>>>
>>>>> onto the brake rotors.
>>>>>
>>>>> All you need to do is put it where it won't be affected by the hot
>>
>>
>> exhaust
>>
>>>>> system. Surely the probe is adequately sealed to deal with water
>>
>>
>> splashing
>>
>>>>> on it. I'd pick a spot where the rocks won't get it, if there is such
>>
>>
>> a
>>
>>>> spot
>>>>
>>>>> ...
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> "Tomes" <askme@here.net> wrote in message
>>>>> news:2C0xf.5343$ZA2.3845@newsread1.news.atl.earthl ink.net...
>>>>>
>>>>>> Hi folks,
>>>>>> One of the things I got for Christmas in a clock/temperature monitor
>>>>
>>>>
>>>> that
>>>>
>>>>>> tells you what the temperature inside the Jeep is and also what
>>>>>> temperature
>>>>>> is outside the jeep. It sticks with sticky velcro anywhere you want
>>
>>
>> to
>>
>>>>>> stick it - I put mine over the glove box so my daughter has
>>
>>
>> something to
>>
>>>>>> do
>>>>>> <grin>. My question for the folks is this:
>>>>>>
>>>>>> It comes with a lead on a long wire for the outside temp sensor and
>>
>>
>> I am
>>
>>>>>> having an indecisive time coming up with a spot to stick it. The
>>>>>> literature
>>>>>> (the deep thought stuff on the packaging) suggests in the door
>>
>>
>> frame,
>>
>>>> but
>>>>
>>>>>> on
>>>>>> this Jeep the doors are off most of the summer as much as I can get
>>
>>
>> away
>>
>>>>>> with. The idea here is it beeps when freezing to warn for black ice
>>>>>> possibility. It needs to stay relatively dry and not be affected by
>>>>
>>>>
>>>> motor
>>>>
>>>>>> heat. It has maybe 8 feet of wire. Suggestions?
>>>>>> Thanks folks,
>>>>>> Tomes
>>>>>> 02 TJ
>>>>>>
>>>>>>
>>>>>
>>
>>
> I'd guess that the "car wash" warning had more to do with it not getting
> broomed off by the RoboWash brushes.
>
> There can be a fair bit of difference in temperature with just a few
> feet of elevation change, and the air can be a good deal warmer than the
> surface you're driving on and it can make a difference -- 33F vs. 31F.
> If I were using it as an icing indicator I'd want it down by the
> pavement surface.
With very few exceptions, the air is always colder than the surface,
even beginning as close as a few centimeters above and or below the
surface. Over solid ground, in all my years measuring these trivia,
even when you think you might, if there was any insolation at all, the
surface would be warmer than air just a few CM above it. Frozen ground
on occasion would be colder, but generally lightly colored with no
insolation. Over areas with canyons and other places where air from
well beneath the roadway can get near the roadway, you are more likely
to run into colder surfaces. If the minor degree difference in mounting
location is taken by the driver as anything significant, that driver is
a sliding accident just waiting to happen. There is more temp
difference along a single mile of typical roadway than any trivia
vertically.
>
> Tomes wrote:
>
>> It's just that on the packaging it noted to keep the sensor out of the
>> 'way
>> of the car wash' or somesuch; it looks sealed enough though. Maybe the
>> peril is that it falls off under water pressure spray, not that it will
>> leak. Would the temperature be much different at these two elevations
>> you
>> think? This one audibly alarms at 32 degrees too for the black ice
>> alert.
>> Tomes
>>
>> "Mike Romain" <romainm@sympatico.ca> wrote in message
>> news:43C98DDC.5F17AE2@sympatico.ca...
>>
>>> The one in our old Volvo was below the front bumper to pick up the road
>>> temperature. It went red at 32 to let you know to watch for black ice.
>>>
>>> Mike
>>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>> 88 Cherokee 235 BFG AT's
>>> Canadian Off Road Trips Photos: Non members can still view!
>>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>> (More Off Road album links at bottom of the view page)
>>>
>>> Tomes wrote:
>>>
>>>> Thanks Jeff. Right now I am running it under the carpet, out the back
>>
>>
>> door
>>
>>>> and mounting it on the bottom of the 3rd brake light. We will see how
>>
>>
>> that
>>
>>>> works out. It is in the elements and somewhat protected.
>>>> Tomes
>>>>
>>>> "Jeff Strickland" <crwlr@yahoo.com> wrote in message
>>>> news:vdidndNoI_1l9VTenZ2dnUVZ_tydnZ2d@ez2.net...
>>>>
>>>>> On my BMW, the probe is mounted in one of the aor ducts that direct
>>
>>
>> cold
>>
>>>> air
>>>>
>>>>> onto the brake rotors.
>>>>>
>>>>> All you need to do is put it where it won't be affected by the hot
>>
>>
>> exhaust
>>
>>>>> system. Surely the probe is adequately sealed to deal with water
>>
>>
>> splashing
>>
>>>>> on it. I'd pick a spot where the rocks won't get it, if there is such
>>
>>
>> a
>>
>>>> spot
>>>>
>>>>> ...
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> "Tomes" <askme@here.net> wrote in message
>>>>> news:2C0xf.5343$ZA2.3845@newsread1.news.atl.earthl ink.net...
>>>>>
>>>>>> Hi folks,
>>>>>> One of the things I got for Christmas in a clock/temperature monitor
>>>>
>>>>
>>>> that
>>>>
>>>>>> tells you what the temperature inside the Jeep is and also what
>>>>>> temperature
>>>>>> is outside the jeep. It sticks with sticky velcro anywhere you want
>>
>>
>> to
>>
>>>>>> stick it - I put mine over the glove box so my daughter has
>>
>>
>> something to
>>
>>>>>> do
>>>>>> <grin>. My question for the folks is this:
>>>>>>
>>>>>> It comes with a lead on a long wire for the outside temp sensor and
>>
>>
>> I am
>>
>>>>>> having an indecisive time coming up with a spot to stick it. The
>>>>>> literature
>>>>>> (the deep thought stuff on the packaging) suggests in the door
>>
>>
>> frame,
>>
>>>> but
>>>>
>>>>>> on
>>>>>> this Jeep the doors are off most of the summer as much as I can get
>>
>>
>> away
>>
>>>>>> with. The idea here is it beeps when freezing to warn for black ice
>>>>>> possibility. It needs to stay relatively dry and not be affected by
>>>>
>>>>
>>>> motor
>>>>
>>>>>> heat. It has maybe 8 feet of wire. Suggestions?
>>>>>> Thanks folks,
>>>>>> Tomes
>>>>>> 02 TJ
>>>>>>
>>>>>>
>>>>>
>>
>>
01-15-2006, 12:27 PM
#67
Guest
Posts: n/a
Re: Interior-Exterior Thermometer
Lee Ayrton proclaimed:
> I'd guess that the "car wash" warning had more to do with it not getting
> broomed off by the RoboWash brushes.
>
> There can be a fair bit of difference in temperature with just a few
> feet of elevation change, and the air can be a good deal warmer than the
> surface you're driving on and it can make a difference -- 33F vs. 31F.
> If I were using it as an icing indicator I'd want it down by the
> pavement surface.
With very few exceptions, the air is always colder than the surface,
even beginning as close as a few centimeters above and or below the
surface. Over solid ground, in all my years measuring these trivia,
even when you think you might, if there was any insolation at all, the
surface would be warmer than air just a few CM above it. Frozen ground
on occasion would be colder, but generally lightly colored with no
insolation. Over areas with canyons and other places where air from
well beneath the roadway can get near the roadway, you are more likely
to run into colder surfaces. If the minor degree difference in mounting
location is taken by the driver as anything significant, that driver is
a sliding accident just waiting to happen. There is more temp
difference along a single mile of typical roadway than any trivia
vertically.
>
> Tomes wrote:
>
>> It's just that on the packaging it noted to keep the sensor out of the
>> 'way
>> of the car wash' or somesuch; it looks sealed enough though. Maybe the
>> peril is that it falls off under water pressure spray, not that it will
>> leak. Would the temperature be much different at these two elevations
>> you
>> think? This one audibly alarms at 32 degrees too for the black ice
>> alert.
>> Tomes
>>
>> "Mike Romain" <romainm@sympatico.ca> wrote in message
>> news:43C98DDC.5F17AE2@sympatico.ca...
>>
>>> The one in our old Volvo was below the front bumper to pick up the road
>>> temperature. It went red at 32 to let you know to watch for black ice.
>>>
>>> Mike
>>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>> 88 Cherokee 235 BFG AT's
>>> Canadian Off Road Trips Photos: Non members can still view!
>>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>> (More Off Road album links at bottom of the view page)
>>>
>>> Tomes wrote:
>>>
>>>> Thanks Jeff. Right now I am running it under the carpet, out the back
>>
>>
>> door
>>
>>>> and mounting it on the bottom of the 3rd brake light. We will see how
>>
>>
>> that
>>
>>>> works out. It is in the elements and somewhat protected.
>>>> Tomes
>>>>
>>>> "Jeff Strickland" <crwlr@yahoo.com> wrote in message
>>>> news:vdidndNoI_1l9VTenZ2dnUVZ_tydnZ2d@ez2.net...
>>>>
>>>>> On my BMW, the probe is mounted in one of the aor ducts that direct
>>
>>
>> cold
>>
>>>> air
>>>>
>>>>> onto the brake rotors.
>>>>>
>>>>> All you need to do is put it where it won't be affected by the hot
>>
>>
>> exhaust
>>
>>>>> system. Surely the probe is adequately sealed to deal with water
>>
>>
>> splashing
>>
>>>>> on it. I'd pick a spot where the rocks won't get it, if there is such
>>
>>
>> a
>>
>>>> spot
>>>>
>>>>> ...
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> "Tomes" <askme@here.net> wrote in message
>>>>> news:2C0xf.5343$ZA2.3845@newsread1.news.atl.earthl ink.net...
>>>>>
>>>>>> Hi folks,
>>>>>> One of the things I got for Christmas in a clock/temperature monitor
>>>>
>>>>
>>>> that
>>>>
>>>>>> tells you what the temperature inside the Jeep is and also what
>>>>>> temperature
>>>>>> is outside the jeep. It sticks with sticky velcro anywhere you want
>>
>>
>> to
>>
>>>>>> stick it - I put mine over the glove box so my daughter has
>>
>>
>> something to
>>
>>>>>> do
>>>>>> <grin>. My question for the folks is this:
>>>>>>
>>>>>> It comes with a lead on a long wire for the outside temp sensor and
>>
>>
>> I am
>>
>>>>>> having an indecisive time coming up with a spot to stick it. The
>>>>>> literature
>>>>>> (the deep thought stuff on the packaging) suggests in the door
>>
>>
>> frame,
>>
>>>> but
>>>>
>>>>>> on
>>>>>> this Jeep the doors are off most of the summer as much as I can get
>>
>>
>> away
>>
>>>>>> with. The idea here is it beeps when freezing to warn for black ice
>>>>>> possibility. It needs to stay relatively dry and not be affected by
>>>>
>>>>
>>>> motor
>>>>
>>>>>> heat. It has maybe 8 feet of wire. Suggestions?
>>>>>> Thanks folks,
>>>>>> Tomes
>>>>>> 02 TJ
>>>>>>
>>>>>>
>>>>>
>>
>>
> I'd guess that the "car wash" warning had more to do with it not getting
> broomed off by the RoboWash brushes.
>
> There can be a fair bit of difference in temperature with just a few
> feet of elevation change, and the air can be a good deal warmer than the
> surface you're driving on and it can make a difference -- 33F vs. 31F.
> If I were using it as an icing indicator I'd want it down by the
> pavement surface.
With very few exceptions, the air is always colder than the surface,
even beginning as close as a few centimeters above and or below the
surface. Over solid ground, in all my years measuring these trivia,
even when you think you might, if there was any insolation at all, the
surface would be warmer than air just a few CM above it. Frozen ground
on occasion would be colder, but generally lightly colored with no
insolation. Over areas with canyons and other places where air from
well beneath the roadway can get near the roadway, you are more likely
to run into colder surfaces. If the minor degree difference in mounting
location is taken by the driver as anything significant, that driver is
a sliding accident just waiting to happen. There is more temp
difference along a single mile of typical roadway than any trivia
vertically.
>
> Tomes wrote:
>
>> It's just that on the packaging it noted to keep the sensor out of the
>> 'way
>> of the car wash' or somesuch; it looks sealed enough though. Maybe the
>> peril is that it falls off under water pressure spray, not that it will
>> leak. Would the temperature be much different at these two elevations
>> you
>> think? This one audibly alarms at 32 degrees too for the black ice
>> alert.
>> Tomes
>>
>> "Mike Romain" <romainm@sympatico.ca> wrote in message
>> news:43C98DDC.5F17AE2@sympatico.ca...
>>
>>> The one in our old Volvo was below the front bumper to pick up the road
>>> temperature. It went red at 32 to let you know to watch for black ice.
>>>
>>> Mike
>>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>> 88 Cherokee 235 BFG AT's
>>> Canadian Off Road Trips Photos: Non members can still view!
>>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>> (More Off Road album links at bottom of the view page)
>>>
>>> Tomes wrote:
>>>
>>>> Thanks Jeff. Right now I am running it under the carpet, out the back
>>
>>
>> door
>>
>>>> and mounting it on the bottom of the 3rd brake light. We will see how
>>
>>
>> that
>>
>>>> works out. It is in the elements and somewhat protected.
>>>> Tomes
>>>>
>>>> "Jeff Strickland" <crwlr@yahoo.com> wrote in message
>>>> news:vdidndNoI_1l9VTenZ2dnUVZ_tydnZ2d@ez2.net...
>>>>
>>>>> On my BMW, the probe is mounted in one of the aor ducts that direct
>>
>>
>> cold
>>
>>>> air
>>>>
>>>>> onto the brake rotors.
>>>>>
>>>>> All you need to do is put it where it won't be affected by the hot
>>
>>
>> exhaust
>>
>>>>> system. Surely the probe is adequately sealed to deal with water
>>
>>
>> splashing
>>
>>>>> on it. I'd pick a spot where the rocks won't get it, if there is such
>>
>>
>> a
>>
>>>> spot
>>>>
>>>>> ...
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> "Tomes" <askme@here.net> wrote in message
>>>>> news:2C0xf.5343$ZA2.3845@newsread1.news.atl.earthl ink.net...
>>>>>
>>>>>> Hi folks,
>>>>>> One of the things I got for Christmas in a clock/temperature monitor
>>>>
>>>>
>>>> that
>>>>
>>>>>> tells you what the temperature inside the Jeep is and also what
>>>>>> temperature
>>>>>> is outside the jeep. It sticks with sticky velcro anywhere you want
>>
>>
>> to
>>
>>>>>> stick it - I put mine over the glove box so my daughter has
>>
>>
>> something to
>>
>>>>>> do
>>>>>> <grin>. My question for the folks is this:
>>>>>>
>>>>>> It comes with a lead on a long wire for the outside temp sensor and
>>
>>
>> I am
>>
>>>>>> having an indecisive time coming up with a spot to stick it. The
>>>>>> literature
>>>>>> (the deep thought stuff on the packaging) suggests in the door
>>
>>
>> frame,
>>
>>>> but
>>>>
>>>>>> on
>>>>>> this Jeep the doors are off most of the summer as much as I can get
>>
>>
>> away
>>
>>>>>> with. The idea here is it beeps when freezing to warn for black ice
>>>>>> possibility. It needs to stay relatively dry and not be affected by
>>>>
>>>>
>>>> motor
>>>>
>>>>>> heat. It has maybe 8 feet of wire. Suggestions?
>>>>>> Thanks folks,
>>>>>> Tomes
>>>>>> 02 TJ
>>>>>>
>>>>>>
>>>>>
>>
>>
01-15-2006, 01:06 PM
#68
Guest
Posts: n/a
Re: Interior-Exterior Thermometer
billy ray proclaimed:
> I think what it comes down to is there is really no good place if you want a
> true air temperature.
"True air temperature" is tricky to get with any sensor. Sufficiently so
that the weather bureau has guidelines for constructing an enclosure
that protects the sensor from any direct radiation yet allows free air
flow but goes on to note that you need to then force a small air flow
past a dry sensor before taking a reading. The enclosure is to be
mounted at a standard height above the surface which cannot be rock,
asphalt, etc. And then you are expected to calibrate your equipment
periodically against precision thermometers and even then although the
temps are reported to a tenth of a degree they are really accurate to
only a degree or two. Once you realize all that, plus the general
cheapness, lack of inherent accuracy, and lack of calibration capability
at multiple points across the temperature curve of the typical home
and/or automobile sensor, the location becomes pretty much more self
delusion than worthwile effort. In the air stream but blocked from
direct high speed air flow and moisture is about as good as you are
gonna get. Calibration is possible on some units but is generally done
only at one point--which if it were my sensor would be 32 degrees F.
Then realize that if the temp is 40 or lower, it is a good idea to be
prepared for icing on all but the most unusual real roads.
>
> Anywhere on/underneath the vehicle will be influenced by heat radiation from
> the roadway. Fresh blacktop in the summer sun will be much hotter and even
> in the winter the sun will make the roadway warmer than the air just a bit
> off the road.
The temp over a dark roadway will be hotter, although the vehicle is
moving and there may or may not be enough other vehicles to stir the air
enough to eliminate the differences except on very wide spans of asphalt
like the old runways at Camp Roberts. Anyone who relies on an auto
temp sensor for the degree of accuracy to really predict icing is
kidding themselves anyway. Anything below 40 or so is dangerous.
>
>
>
>
> "Lee Ayrton" <layrton@panix.com> wrote in message
> news:dqdqhj$n1$1@reader2.panix.com...
>
>>I'd guess that the "car wash" warning had more to do with it not getting
>>broomed off by the RoboWash brushes.
>>
>>There can be a fair bit of difference in temperature with just a few feet
>>of elevation change, and the air can be a good deal warmer than the
>>surface you're driving on and it can make a difference -- 33F vs. 31F. If
>>I were using it as an icing indicator I'd want it down by the pavement
>>surface.
>>
>>Tomes wrote:
>>
>>>It's just that on the packaging it noted to keep the sensor out of the
>>>'way
>>>of the car wash' or somesuch; it looks sealed enough though. Maybe the
>>>peril is that it falls off under water pressure spray, not that it will
>>>leak. Would the temperature be much different at these two elevations
>>>you
>>>think? This one audibly alarms at 32 degrees too for the black ice
>>>alert.
>>>Tomes
>>>
>>>"Mike Romain" <romainm@sympatico.ca> wrote in message
>>>news:43C98DDC.5F17AE2@sympatico.ca...
>>>
>>>
>>>>The one in our old Volvo was below the front bumper to pick up the road
>>>>temperature. It went red at 32 to let you know to watch for black ice.
>>>>
>>>>Mike
>>>>86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>>>88 Cherokee 235 BFG AT's
>>>>Canadian Off Road Trips Photos: Non members can still view!
>>>>Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>>>(More Off Road album links at bottom of the view page)
>>>>
>>>>Tomes wrote:
>>>>
>>>>
>>>>>Thanks Jeff. Right now I am running it under the carpet, out the back
>>>
>>>door
>>>
>>>
>>>>>and mounting it on the bottom of the 3rd brake light. We will see how
>>>
>>>that
>>>
>>>
>>>>>works out. It is in the elements and somewhat protected.
>>>>>Tomes
>>>>>
>>>>>"Jeff Strickland" <crwlr@yahoo.com> wrote in message
>>>>>news:vdidndNoI_1l9VTenZ2dnUVZ_tydnZ2d@ez2.net ...
>>>>>
>>>>>
>>>>>>On my BMW, the probe is mounted in one of the aor ducts that direct
>>>
>>>cold
>>>
>>>
>>>>>air
>>>>>
>>>>>
>>>>>>onto the brake rotors.
>>>>>>
>>>>>>All you need to do is put it where it won't be affected by the hot
>>>
>>>exhaust
>>>
>>>
>>>>>>system. Surely the probe is adequately sealed to deal with water
>>>
>>>splashing
>>>
>>>
>>>>>>on it. I'd pick a spot where the rocks won't get it, if there is such
>>>
>>>a
>>>
>>>
>>>>>spot
>>>>>
>>>>>
>>>>>>...
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>"Tomes" <askme@here.net> wrote in message
>>>>>>news:2C0xf.5343$ZA2.3845@newsread1.news.atl. earthlink.net...
>>>>>>
>>>>>>
>>>>>>>Hi folks,
>>>>>>>One of the things I got for Christmas in a clock/temperature monitor
>>>>>
>>>>>that
>>>>>
>>>>>
>>>>>>>tells you what the temperature inside the Jeep is and also what
>>>>>>>temperature
>>>>>>>is outside the jeep. It sticks with sticky velcro anywhere you want
>>>
>>>to
>>>
>>>
>>>>>>>stick it - I put mine over the glove box so my daughter has
>>>
>>>something to
>>>
>>>
>>>>>>>do
>>>>>>><grin>. My question for the folks is this:
>>>>>>>
>>>>>>>It comes with a lead on a long wire for the outside temp sensor and
>>>
>>>I am
>>>
>>>
>>>>>>>having an indecisive time coming up with a spot to stick it. The
>>>>>>>literature
>>>>>>>(the deep thought stuff on the packaging) suggests in the door
>>>
>>>frame,
>>>
>>>
>>>>>but
>>>>>
>>>>>
>>>>>>>on
>>>>>>>this Jeep the doors are off most of the summer as much as I can get
>>>
>>>away
>>>
>>>
>>>>>>>with. The idea here is it beeps when freezing to warn for black ice
>>>>>>>possibility. It needs to stay relatively dry and not be affected by
>>>>>
>>>>>motor
>>>>>
>>>>>
>>>>>>>heat. It has maybe 8 feet of wire. Suggestions?
>>>>>>>Thanks folks,
>>>>>>>Tomes
>>>>>>>02 TJ
>>>>>>>
>>>>>>>
>>>>>>
>
> I think what it comes down to is there is really no good place if you want a
> true air temperature.
"True air temperature" is tricky to get with any sensor. Sufficiently so
that the weather bureau has guidelines for constructing an enclosure
that protects the sensor from any direct radiation yet allows free air
flow but goes on to note that you need to then force a small air flow
past a dry sensor before taking a reading. The enclosure is to be
mounted at a standard height above the surface which cannot be rock,
asphalt, etc. And then you are expected to calibrate your equipment
periodically against precision thermometers and even then although the
temps are reported to a tenth of a degree they are really accurate to
only a degree or two. Once you realize all that, plus the general
cheapness, lack of inherent accuracy, and lack of calibration capability
at multiple points across the temperature curve of the typical home
and/or automobile sensor, the location becomes pretty much more self
delusion than worthwile effort. In the air stream but blocked from
direct high speed air flow and moisture is about as good as you are
gonna get. Calibration is possible on some units but is generally done
only at one point--which if it were my sensor would be 32 degrees F.
Then realize that if the temp is 40 or lower, it is a good idea to be
prepared for icing on all but the most unusual real roads.
>
> Anywhere on/underneath the vehicle will be influenced by heat radiation from
> the roadway. Fresh blacktop in the summer sun will be much hotter and even
> in the winter the sun will make the roadway warmer than the air just a bit
> off the road.
The temp over a dark roadway will be hotter, although the vehicle is
moving and there may or may not be enough other vehicles to stir the air
enough to eliminate the differences except on very wide spans of asphalt
like the old runways at Camp Roberts. Anyone who relies on an auto
temp sensor for the degree of accuracy to really predict icing is
kidding themselves anyway. Anything below 40 or so is dangerous.
>
>
>
>
> "Lee Ayrton" <layrton@panix.com> wrote in message
> news:dqdqhj$n1$1@reader2.panix.com...
>
>>I'd guess that the "car wash" warning had more to do with it not getting
>>broomed off by the RoboWash brushes.
>>
>>There can be a fair bit of difference in temperature with just a few feet
>>of elevation change, and the air can be a good deal warmer than the
>>surface you're driving on and it can make a difference -- 33F vs. 31F. If
>>I were using it as an icing indicator I'd want it down by the pavement
>>surface.
>>
>>Tomes wrote:
>>
>>>It's just that on the packaging it noted to keep the sensor out of the
>>>'way
>>>of the car wash' or somesuch; it looks sealed enough though. Maybe the
>>>peril is that it falls off under water pressure spray, not that it will
>>>leak. Would the temperature be much different at these two elevations
>>>you
>>>think? This one audibly alarms at 32 degrees too for the black ice
>>>alert.
>>>Tomes
>>>
>>>"Mike Romain" <romainm@sympatico.ca> wrote in message
>>>news:43C98DDC.5F17AE2@sympatico.ca...
>>>
>>>
>>>>The one in our old Volvo was below the front bumper to pick up the road
>>>>temperature. It went red at 32 to let you know to watch for black ice.
>>>>
>>>>Mike
>>>>86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>>>88 Cherokee 235 BFG AT's
>>>>Canadian Off Road Trips Photos: Non members can still view!
>>>>Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>>>(More Off Road album links at bottom of the view page)
>>>>
>>>>Tomes wrote:
>>>>
>>>>
>>>>>Thanks Jeff. Right now I am running it under the carpet, out the back
>>>
>>>door
>>>
>>>
>>>>>and mounting it on the bottom of the 3rd brake light. We will see how
>>>
>>>that
>>>
>>>
>>>>>works out. It is in the elements and somewhat protected.
>>>>>Tomes
>>>>>
>>>>>"Jeff Strickland" <crwlr@yahoo.com> wrote in message
>>>>>news:vdidndNoI_1l9VTenZ2dnUVZ_tydnZ2d@ez2.net ...
>>>>>
>>>>>
>>>>>>On my BMW, the probe is mounted in one of the aor ducts that direct
>>>
>>>cold
>>>
>>>
>>>>>air
>>>>>
>>>>>
>>>>>>onto the brake rotors.
>>>>>>
>>>>>>All you need to do is put it where it won't be affected by the hot
>>>
>>>exhaust
>>>
>>>
>>>>>>system. Surely the probe is adequately sealed to deal with water
>>>
>>>splashing
>>>
>>>
>>>>>>on it. I'd pick a spot where the rocks won't get it, if there is such
>>>
>>>a
>>>
>>>
>>>>>spot
>>>>>
>>>>>
>>>>>>...
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>"Tomes" <askme@here.net> wrote in message
>>>>>>news:2C0xf.5343$ZA2.3845@newsread1.news.atl. earthlink.net...
>>>>>>
>>>>>>
>>>>>>>Hi folks,
>>>>>>>One of the things I got for Christmas in a clock/temperature monitor
>>>>>
>>>>>that
>>>>>
>>>>>
>>>>>>>tells you what the temperature inside the Jeep is and also what
>>>>>>>temperature
>>>>>>>is outside the jeep. It sticks with sticky velcro anywhere you want
>>>
>>>to
>>>
>>>
>>>>>>>stick it - I put mine over the glove box so my daughter has
>>>
>>>something to
>>>
>>>
>>>>>>>do
>>>>>>><grin>. My question for the folks is this:
>>>>>>>
>>>>>>>It comes with a lead on a long wire for the outside temp sensor and
>>>
>>>I am
>>>
>>>
>>>>>>>having an indecisive time coming up with a spot to stick it. The
>>>>>>>literature
>>>>>>>(the deep thought stuff on the packaging) suggests in the door
>>>
>>>frame,
>>>
>>>
>>>>>but
>>>>>
>>>>>
>>>>>>>on
>>>>>>>this Jeep the doors are off most of the summer as much as I can get
>>>
>>>away
>>>
>>>
>>>>>>>with. The idea here is it beeps when freezing to warn for black ice
>>>>>>>possibility. It needs to stay relatively dry and not be affected by
>>>>>
>>>>>motor
>>>>>
>>>>>
>>>>>>>heat. It has maybe 8 feet of wire. Suggestions?
>>>>>>>Thanks folks,
>>>>>>>Tomes
>>>>>>>02 TJ
>>>>>>>
>>>>>>>
>>>>>>
>
01-15-2006, 01:06 PM
#69
Guest
Posts: n/a
Re: Interior-Exterior Thermometer
billy ray proclaimed:
> I think what it comes down to is there is really no good place if you want a
> true air temperature.
"True air temperature" is tricky to get with any sensor. Sufficiently so
that the weather bureau has guidelines for constructing an enclosure
that protects the sensor from any direct radiation yet allows free air
flow but goes on to note that you need to then force a small air flow
past a dry sensor before taking a reading. The enclosure is to be
mounted at a standard height above the surface which cannot be rock,
asphalt, etc. And then you are expected to calibrate your equipment
periodically against precision thermometers and even then although the
temps are reported to a tenth of a degree they are really accurate to
only a degree or two. Once you realize all that, plus the general
cheapness, lack of inherent accuracy, and lack of calibration capability
at multiple points across the temperature curve of the typical home
and/or automobile sensor, the location becomes pretty much more self
delusion than worthwile effort. In the air stream but blocked from
direct high speed air flow and moisture is about as good as you are
gonna get. Calibration is possible on some units but is generally done
only at one point--which if it were my sensor would be 32 degrees F.
Then realize that if the temp is 40 or lower, it is a good idea to be
prepared for icing on all but the most unusual real roads.
>
> Anywhere on/underneath the vehicle will be influenced by heat radiation from
> the roadway. Fresh blacktop in the summer sun will be much hotter and even
> in the winter the sun will make the roadway warmer than the air just a bit
> off the road.
The temp over a dark roadway will be hotter, although the vehicle is
moving and there may or may not be enough other vehicles to stir the air
enough to eliminate the differences except on very wide spans of asphalt
like the old runways at Camp Roberts. Anyone who relies on an auto
temp sensor for the degree of accuracy to really predict icing is
kidding themselves anyway. Anything below 40 or so is dangerous.
>
>
>
>
> "Lee Ayrton" <layrton@panix.com> wrote in message
> news:dqdqhj$n1$1@reader2.panix.com...
>
>>I'd guess that the "car wash" warning had more to do with it not getting
>>broomed off by the RoboWash brushes.
>>
>>There can be a fair bit of difference in temperature with just a few feet
>>of elevation change, and the air can be a good deal warmer than the
>>surface you're driving on and it can make a difference -- 33F vs. 31F. If
>>I were using it as an icing indicator I'd want it down by the pavement
>>surface.
>>
>>Tomes wrote:
>>
>>>It's just that on the packaging it noted to keep the sensor out of the
>>>'way
>>>of the car wash' or somesuch; it looks sealed enough though. Maybe the
>>>peril is that it falls off under water pressure spray, not that it will
>>>leak. Would the temperature be much different at these two elevations
>>>you
>>>think? This one audibly alarms at 32 degrees too for the black ice
>>>alert.
>>>Tomes
>>>
>>>"Mike Romain" <romainm@sympatico.ca> wrote in message
>>>news:43C98DDC.5F17AE2@sympatico.ca...
>>>
>>>
>>>>The one in our old Volvo was below the front bumper to pick up the road
>>>>temperature. It went red at 32 to let you know to watch for black ice.
>>>>
>>>>Mike
>>>>86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>>>88 Cherokee 235 BFG AT's
>>>>Canadian Off Road Trips Photos: Non members can still view!
>>>>Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>>>(More Off Road album links at bottom of the view page)
>>>>
>>>>Tomes wrote:
>>>>
>>>>
>>>>>Thanks Jeff. Right now I am running it under the carpet, out the back
>>>
>>>door
>>>
>>>
>>>>>and mounting it on the bottom of the 3rd brake light. We will see how
>>>
>>>that
>>>
>>>
>>>>>works out. It is in the elements and somewhat protected.
>>>>>Tomes
>>>>>
>>>>>"Jeff Strickland" <crwlr@yahoo.com> wrote in message
>>>>>news:vdidndNoI_1l9VTenZ2dnUVZ_tydnZ2d@ez2.net ...
>>>>>
>>>>>
>>>>>>On my BMW, the probe is mounted in one of the aor ducts that direct
>>>
>>>cold
>>>
>>>
>>>>>air
>>>>>
>>>>>
>>>>>>onto the brake rotors.
>>>>>>
>>>>>>All you need to do is put it where it won't be affected by the hot
>>>
>>>exhaust
>>>
>>>
>>>>>>system. Surely the probe is adequately sealed to deal with water
>>>
>>>splashing
>>>
>>>
>>>>>>on it. I'd pick a spot where the rocks won't get it, if there is such
>>>
>>>a
>>>
>>>
>>>>>spot
>>>>>
>>>>>
>>>>>>...
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>"Tomes" <askme@here.net> wrote in message
>>>>>>news:2C0xf.5343$ZA2.3845@newsread1.news.atl. earthlink.net...
>>>>>>
>>>>>>
>>>>>>>Hi folks,
>>>>>>>One of the things I got for Christmas in a clock/temperature monitor
>>>>>
>>>>>that
>>>>>
>>>>>
>>>>>>>tells you what the temperature inside the Jeep is and also what
>>>>>>>temperature
>>>>>>>is outside the jeep. It sticks with sticky velcro anywhere you want
>>>
>>>to
>>>
>>>
>>>>>>>stick it - I put mine over the glove box so my daughter has
>>>
>>>something to
>>>
>>>
>>>>>>>do
>>>>>>><grin>. My question for the folks is this:
>>>>>>>
>>>>>>>It comes with a lead on a long wire for the outside temp sensor and
>>>
>>>I am
>>>
>>>
>>>>>>>having an indecisive time coming up with a spot to stick it. The
>>>>>>>literature
>>>>>>>(the deep thought stuff on the packaging) suggests in the door
>>>
>>>frame,
>>>
>>>
>>>>>but
>>>>>
>>>>>
>>>>>>>on
>>>>>>>this Jeep the doors are off most of the summer as much as I can get
>>>
>>>away
>>>
>>>
>>>>>>>with. The idea here is it beeps when freezing to warn for black ice
>>>>>>>possibility. It needs to stay relatively dry and not be affected by
>>>>>
>>>>>motor
>>>>>
>>>>>
>>>>>>>heat. It has maybe 8 feet of wire. Suggestions?
>>>>>>>Thanks folks,
>>>>>>>Tomes
>>>>>>>02 TJ
>>>>>>>
>>>>>>>
>>>>>>
>
> I think what it comes down to is there is really no good place if you want a
> true air temperature.
"True air temperature" is tricky to get with any sensor. Sufficiently so
that the weather bureau has guidelines for constructing an enclosure
that protects the sensor from any direct radiation yet allows free air
flow but goes on to note that you need to then force a small air flow
past a dry sensor before taking a reading. The enclosure is to be
mounted at a standard height above the surface which cannot be rock,
asphalt, etc. And then you are expected to calibrate your equipment
periodically against precision thermometers and even then although the
temps are reported to a tenth of a degree they are really accurate to
only a degree or two. Once you realize all that, plus the general
cheapness, lack of inherent accuracy, and lack of calibration capability
at multiple points across the temperature curve of the typical home
and/or automobile sensor, the location becomes pretty much more self
delusion than worthwile effort. In the air stream but blocked from
direct high speed air flow and moisture is about as good as you are
gonna get. Calibration is possible on some units but is generally done
only at one point--which if it were my sensor would be 32 degrees F.
Then realize that if the temp is 40 or lower, it is a good idea to be
prepared for icing on all but the most unusual real roads.
>
> Anywhere on/underneath the vehicle will be influenced by heat radiation from
> the roadway. Fresh blacktop in the summer sun will be much hotter and even
> in the winter the sun will make the roadway warmer than the air just a bit
> off the road.
The temp over a dark roadway will be hotter, although the vehicle is
moving and there may or may not be enough other vehicles to stir the air
enough to eliminate the differences except on very wide spans of asphalt
like the old runways at Camp Roberts. Anyone who relies on an auto
temp sensor for the degree of accuracy to really predict icing is
kidding themselves anyway. Anything below 40 or so is dangerous.
>
>
>
>
> "Lee Ayrton" <layrton@panix.com> wrote in message
> news:dqdqhj$n1$1@reader2.panix.com...
>
>>I'd guess that the "car wash" warning had more to do with it not getting
>>broomed off by the RoboWash brushes.
>>
>>There can be a fair bit of difference in temperature with just a few feet
>>of elevation change, and the air can be a good deal warmer than the
>>surface you're driving on and it can make a difference -- 33F vs. 31F. If
>>I were using it as an icing indicator I'd want it down by the pavement
>>surface.
>>
>>Tomes wrote:
>>
>>>It's just that on the packaging it noted to keep the sensor out of the
>>>'way
>>>of the car wash' or somesuch; it looks sealed enough though. Maybe the
>>>peril is that it falls off under water pressure spray, not that it will
>>>leak. Would the temperature be much different at these two elevations
>>>you
>>>think? This one audibly alarms at 32 degrees too for the black ice
>>>alert.
>>>Tomes
>>>
>>>"Mike Romain" <romainm@sympatico.ca> wrote in message
>>>news:43C98DDC.5F17AE2@sympatico.ca...
>>>
>>>
>>>>The one in our old Volvo was below the front bumper to pick up the road
>>>>temperature. It went red at 32 to let you know to watch for black ice.
>>>>
>>>>Mike
>>>>86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>>>88 Cherokee 235 BFG AT's
>>>>Canadian Off Road Trips Photos: Non members can still view!
>>>>Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>>>(More Off Road album links at bottom of the view page)
>>>>
>>>>Tomes wrote:
>>>>
>>>>
>>>>>Thanks Jeff. Right now I am running it under the carpet, out the back
>>>
>>>door
>>>
>>>
>>>>>and mounting it on the bottom of the 3rd brake light. We will see how
>>>
>>>that
>>>
>>>
>>>>>works out. It is in the elements and somewhat protected.
>>>>>Tomes
>>>>>
>>>>>"Jeff Strickland" <crwlr@yahoo.com> wrote in message
>>>>>news:vdidndNoI_1l9VTenZ2dnUVZ_tydnZ2d@ez2.net ...
>>>>>
>>>>>
>>>>>>On my BMW, the probe is mounted in one of the aor ducts that direct
>>>
>>>cold
>>>
>>>
>>>>>air
>>>>>
>>>>>
>>>>>>onto the brake rotors.
>>>>>>
>>>>>>All you need to do is put it where it won't be affected by the hot
>>>
>>>exhaust
>>>
>>>
>>>>>>system. Surely the probe is adequately sealed to deal with water
>>>
>>>splashing
>>>
>>>
>>>>>>on it. I'd pick a spot where the rocks won't get it, if there is such
>>>
>>>a
>>>
>>>
>>>>>spot
>>>>>
>>>>>
>>>>>>...
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>"Tomes" <askme@here.net> wrote in message
>>>>>>news:2C0xf.5343$ZA2.3845@newsread1.news.atl. earthlink.net...
>>>>>>
>>>>>>
>>>>>>>Hi folks,
>>>>>>>One of the things I got for Christmas in a clock/temperature monitor
>>>>>
>>>>>that
>>>>>
>>>>>
>>>>>>>tells you what the temperature inside the Jeep is and also what
>>>>>>>temperature
>>>>>>>is outside the jeep. It sticks with sticky velcro anywhere you want
>>>
>>>to
>>>
>>>
>>>>>>>stick it - I put mine over the glove box so my daughter has
>>>
>>>something to
>>>
>>>
>>>>>>>do
>>>>>>><grin>. My question for the folks is this:
>>>>>>>
>>>>>>>It comes with a lead on a long wire for the outside temp sensor and
>>>
>>>I am
>>>
>>>
>>>>>>>having an indecisive time coming up with a spot to stick it. The
>>>>>>>literature
>>>>>>>(the deep thought stuff on the packaging) suggests in the door
>>>
>>>frame,
>>>
>>>
>>>>>but
>>>>>
>>>>>
>>>>>>>on
>>>>>>>this Jeep the doors are off most of the summer as much as I can get
>>>
>>>away
>>>
>>>
>>>>>>>with. The idea here is it beeps when freezing to warn for black ice
>>>>>>>possibility. It needs to stay relatively dry and not be affected by
>>>>>
>>>>>motor
>>>>>
>>>>>
>>>>>>>heat. It has maybe 8 feet of wire. Suggestions?
>>>>>>>Thanks folks,
>>>>>>>Tomes
>>>>>>>02 TJ
>>>>>>>
>>>>>>>
>>>>>>
>
01-15-2006, 01:06 PM
#70
Guest
Posts: n/a
Re: Interior-Exterior Thermometer
billy ray proclaimed:
> I think what it comes down to is there is really no good place if you want a
> true air temperature.
"True air temperature" is tricky to get with any sensor. Sufficiently so
that the weather bureau has guidelines for constructing an enclosure
that protects the sensor from any direct radiation yet allows free air
flow but goes on to note that you need to then force a small air flow
past a dry sensor before taking a reading. The enclosure is to be
mounted at a standard height above the surface which cannot be rock,
asphalt, etc. And then you are expected to calibrate your equipment
periodically against precision thermometers and even then although the
temps are reported to a tenth of a degree they are really accurate to
only a degree or two. Once you realize all that, plus the general
cheapness, lack of inherent accuracy, and lack of calibration capability
at multiple points across the temperature curve of the typical home
and/or automobile sensor, the location becomes pretty much more self
delusion than worthwile effort. In the air stream but blocked from
direct high speed air flow and moisture is about as good as you are
gonna get. Calibration is possible on some units but is generally done
only at one point--which if it were my sensor would be 32 degrees F.
Then realize that if the temp is 40 or lower, it is a good idea to be
prepared for icing on all but the most unusual real roads.
>
> Anywhere on/underneath the vehicle will be influenced by heat radiation from
> the roadway. Fresh blacktop in the summer sun will be much hotter and even
> in the winter the sun will make the roadway warmer than the air just a bit
> off the road.
The temp over a dark roadway will be hotter, although the vehicle is
moving and there may or may not be enough other vehicles to stir the air
enough to eliminate the differences except on very wide spans of asphalt
like the old runways at Camp Roberts. Anyone who relies on an auto
temp sensor for the degree of accuracy to really predict icing is
kidding themselves anyway. Anything below 40 or so is dangerous.
>
>
>
>
> "Lee Ayrton" <layrton@panix.com> wrote in message
> news:dqdqhj$n1$1@reader2.panix.com...
>
>>I'd guess that the "car wash" warning had more to do with it not getting
>>broomed off by the RoboWash brushes.
>>
>>There can be a fair bit of difference in temperature with just a few feet
>>of elevation change, and the air can be a good deal warmer than the
>>surface you're driving on and it can make a difference -- 33F vs. 31F. If
>>I were using it as an icing indicator I'd want it down by the pavement
>>surface.
>>
>>Tomes wrote:
>>
>>>It's just that on the packaging it noted to keep the sensor out of the
>>>'way
>>>of the car wash' or somesuch; it looks sealed enough though. Maybe the
>>>peril is that it falls off under water pressure spray, not that it will
>>>leak. Would the temperature be much different at these two elevations
>>>you
>>>think? This one audibly alarms at 32 degrees too for the black ice
>>>alert.
>>>Tomes
>>>
>>>"Mike Romain" <romainm@sympatico.ca> wrote in message
>>>news:43C98DDC.5F17AE2@sympatico.ca...
>>>
>>>
>>>>The one in our old Volvo was below the front bumper to pick up the road
>>>>temperature. It went red at 32 to let you know to watch for black ice.
>>>>
>>>>Mike
>>>>86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>>>88 Cherokee 235 BFG AT's
>>>>Canadian Off Road Trips Photos: Non members can still view!
>>>>Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>>>(More Off Road album links at bottom of the view page)
>>>>
>>>>Tomes wrote:
>>>>
>>>>
>>>>>Thanks Jeff. Right now I am running it under the carpet, out the back
>>>
>>>door
>>>
>>>
>>>>>and mounting it on the bottom of the 3rd brake light. We will see how
>>>
>>>that
>>>
>>>
>>>>>works out. It is in the elements and somewhat protected.
>>>>>Tomes
>>>>>
>>>>>"Jeff Strickland" <crwlr@yahoo.com> wrote in message
>>>>>news:vdidndNoI_1l9VTenZ2dnUVZ_tydnZ2d@ez2.net ...
>>>>>
>>>>>
>>>>>>On my BMW, the probe is mounted in one of the aor ducts that direct
>>>
>>>cold
>>>
>>>
>>>>>air
>>>>>
>>>>>
>>>>>>onto the brake rotors.
>>>>>>
>>>>>>All you need to do is put it where it won't be affected by the hot
>>>
>>>exhaust
>>>
>>>
>>>>>>system. Surely the probe is adequately sealed to deal with water
>>>
>>>splashing
>>>
>>>
>>>>>>on it. I'd pick a spot where the rocks won't get it, if there is such
>>>
>>>a
>>>
>>>
>>>>>spot
>>>>>
>>>>>
>>>>>>...
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>"Tomes" <askme@here.net> wrote in message
>>>>>>news:2C0xf.5343$ZA2.3845@newsread1.news.atl. earthlink.net...
>>>>>>
>>>>>>
>>>>>>>Hi folks,
>>>>>>>One of the things I got for Christmas in a clock/temperature monitor
>>>>>
>>>>>that
>>>>>
>>>>>
>>>>>>>tells you what the temperature inside the Jeep is and also what
>>>>>>>temperature
>>>>>>>is outside the jeep. It sticks with sticky velcro anywhere you want
>>>
>>>to
>>>
>>>
>>>>>>>stick it - I put mine over the glove box so my daughter has
>>>
>>>something to
>>>
>>>
>>>>>>>do
>>>>>>><grin>. My question for the folks is this:
>>>>>>>
>>>>>>>It comes with a lead on a long wire for the outside temp sensor and
>>>
>>>I am
>>>
>>>
>>>>>>>having an indecisive time coming up with a spot to stick it. The
>>>>>>>literature
>>>>>>>(the deep thought stuff on the packaging) suggests in the door
>>>
>>>frame,
>>>
>>>
>>>>>but
>>>>>
>>>>>
>>>>>>>on
>>>>>>>this Jeep the doors are off most of the summer as much as I can get
>>>
>>>away
>>>
>>>
>>>>>>>with. The idea here is it beeps when freezing to warn for black ice
>>>>>>>possibility. It needs to stay relatively dry and not be affected by
>>>>>
>>>>>motor
>>>>>
>>>>>
>>>>>>>heat. It has maybe 8 feet of wire. Suggestions?
>>>>>>>Thanks folks,
>>>>>>>Tomes
>>>>>>>02 TJ
>>>>>>>
>>>>>>>
>>>>>>
>
> I think what it comes down to is there is really no good place if you want a
> true air temperature.
"True air temperature" is tricky to get with any sensor. Sufficiently so
that the weather bureau has guidelines for constructing an enclosure
that protects the sensor from any direct radiation yet allows free air
flow but goes on to note that you need to then force a small air flow
past a dry sensor before taking a reading. The enclosure is to be
mounted at a standard height above the surface which cannot be rock,
asphalt, etc. And then you are expected to calibrate your equipment
periodically against precision thermometers and even then although the
temps are reported to a tenth of a degree they are really accurate to
only a degree or two. Once you realize all that, plus the general
cheapness, lack of inherent accuracy, and lack of calibration capability
at multiple points across the temperature curve of the typical home
and/or automobile sensor, the location becomes pretty much more self
delusion than worthwile effort. In the air stream but blocked from
direct high speed air flow and moisture is about as good as you are
gonna get. Calibration is possible on some units but is generally done
only at one point--which if it were my sensor would be 32 degrees F.
Then realize that if the temp is 40 or lower, it is a good idea to be
prepared for icing on all but the most unusual real roads.
>
> Anywhere on/underneath the vehicle will be influenced by heat radiation from
> the roadway. Fresh blacktop in the summer sun will be much hotter and even
> in the winter the sun will make the roadway warmer than the air just a bit
> off the road.
The temp over a dark roadway will be hotter, although the vehicle is
moving and there may or may not be enough other vehicles to stir the air
enough to eliminate the differences except on very wide spans of asphalt
like the old runways at Camp Roberts. Anyone who relies on an auto
temp sensor for the degree of accuracy to really predict icing is
kidding themselves anyway. Anything below 40 or so is dangerous.
>
>
>
>
> "Lee Ayrton" <layrton@panix.com> wrote in message
> news:dqdqhj$n1$1@reader2.panix.com...
>
>>I'd guess that the "car wash" warning had more to do with it not getting
>>broomed off by the RoboWash brushes.
>>
>>There can be a fair bit of difference in temperature with just a few feet
>>of elevation change, and the air can be a good deal warmer than the
>>surface you're driving on and it can make a difference -- 33F vs. 31F. If
>>I were using it as an icing indicator I'd want it down by the pavement
>>surface.
>>
>>Tomes wrote:
>>
>>>It's just that on the packaging it noted to keep the sensor out of the
>>>'way
>>>of the car wash' or somesuch; it looks sealed enough though. Maybe the
>>>peril is that it falls off under water pressure spray, not that it will
>>>leak. Would the temperature be much different at these two elevations
>>>you
>>>think? This one audibly alarms at 32 degrees too for the black ice
>>>alert.
>>>Tomes
>>>
>>>"Mike Romain" <romainm@sympatico.ca> wrote in message
>>>news:43C98DDC.5F17AE2@sympatico.ca...
>>>
>>>
>>>>The one in our old Volvo was below the front bumper to pick up the road
>>>>temperature. It went red at 32 to let you know to watch for black ice.
>>>>
>>>>Mike
>>>>86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>>>88 Cherokee 235 BFG AT's
>>>>Canadian Off Road Trips Photos: Non members can still view!
>>>>Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>>>(More Off Road album links at bottom of the view page)
>>>>
>>>>Tomes wrote:
>>>>
>>>>
>>>>>Thanks Jeff. Right now I am running it under the carpet, out the back
>>>
>>>door
>>>
>>>
>>>>>and mounting it on the bottom of the 3rd brake light. We will see how
>>>
>>>that
>>>
>>>
>>>>>works out. It is in the elements and somewhat protected.
>>>>>Tomes
>>>>>
>>>>>"Jeff Strickland" <crwlr@yahoo.com> wrote in message
>>>>>news:vdidndNoI_1l9VTenZ2dnUVZ_tydnZ2d@ez2.net ...
>>>>>
>>>>>
>>>>>>On my BMW, the probe is mounted in one of the aor ducts that direct
>>>
>>>cold
>>>
>>>
>>>>>air
>>>>>
>>>>>
>>>>>>onto the brake rotors.
>>>>>>
>>>>>>All you need to do is put it where it won't be affected by the hot
>>>
>>>exhaust
>>>
>>>
>>>>>>system. Surely the probe is adequately sealed to deal with water
>>>
>>>splashing
>>>
>>>
>>>>>>on it. I'd pick a spot where the rocks won't get it, if there is such
>>>
>>>a
>>>
>>>
>>>>>spot
>>>>>
>>>>>
>>>>>>...
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>"Tomes" <askme@here.net> wrote in message
>>>>>>news:2C0xf.5343$ZA2.3845@newsread1.news.atl. earthlink.net...
>>>>>>
>>>>>>
>>>>>>>Hi folks,
>>>>>>>One of the things I got for Christmas in a clock/temperature monitor
>>>>>
>>>>>that
>>>>>
>>>>>
>>>>>>>tells you what the temperature inside the Jeep is and also what
>>>>>>>temperature
>>>>>>>is outside the jeep. It sticks with sticky velcro anywhere you want
>>>
>>>to
>>>
>>>
>>>>>>>stick it - I put mine over the glove box so my daughter has
>>>
>>>something to
>>>
>>>
>>>>>>>do
>>>>>>><grin>. My question for the folks is this:
>>>>>>>
>>>>>>>It comes with a lead on a long wire for the outside temp sensor and
>>>
>>>I am
>>>
>>>
>>>>>>>having an indecisive time coming up with a spot to stick it. The
>>>>>>>literature
>>>>>>>(the deep thought stuff on the packaging) suggests in the door
>>>
>>>frame,
>>>
>>>
>>>>>but
>>>>>
>>>>>
>>>>>>>on
>>>>>>>this Jeep the doors are off most of the summer as much as I can get
>>>
>>>away
>>>
>>>
>>>>>>>with. The idea here is it beeps when freezing to warn for black ice
>>>>>>>possibility. It needs to stay relatively dry and not be affected by
>>>>>
>>>>>motor
>>>>>
>>>>>
>>>>>>>heat. It has maybe 8 feet of wire. Suggestions?
>>>>>>>Thanks folks,
>>>>>>>Tomes
>>>>>>>02 TJ
>>>>>>>
>>>>>>>
>>>>>>
>
