Thermometers - where are the sensors and how can we calibrate them?

[Tuan]

How many thermometers are there? Inside, outside, liquid of cooling system of battery pack?

 

[Todd Burch]

Quite a few. Most are probably thermocouples, do not need calibration, and are not user-servicable unless you enjoy voiding warranties .

 

[skilly]

They are actually not that bad in their accuracy. The challenge is typically their placement if you are getting a reading that seems off.

 

[Tuan]

Okay, here's one that's off today. Weather app says 89F as outside temp. Android Tesla App says 131F inside temp. Went out to the car to check on the temp on dashboard, 99F. Digital thermometer I placed in the car to test (out of sunlight) says 120F

 

[RDoc]

I wouldn't be surprised that once you open the door, cooler air comes in and starts changing the temperature of the interior, but very non-uniformly because of varying local heat capacity, etc.

 

[DavidB]

The passenger compartment temperature sensor is behind the grill that is just above the 12 volt power socket, below the center arm rest.

The sideways picture in this thread shows it well:
http://www.teslamotorsclub.com/showthread.php/28863-Grill-Below-Arm-Rest

There are two problems with this placement: (1) Vents are often directed toward this grill, and (2) the air duct for the vent on the back of the center console runs below the center console without thermal insulation and the connections leak air.

 

[Tuan]

The dashboard temperature display is for OUTSIDE, right? It was at 99F when my weather app said 89F (I also verified that with accuweather.com). That was 10F off. When I drove around for 15 min, dashboard temp went down to 93F. I actually didn't open the door when I peeked in to look at the thermometer I placed inside on the seat (out of sunlight though). My test thermometer is calibrated.

Right now, everything is spot on. Dashboard temp says 61F, which matches my yahoo weather app on my phone. The calibrated thermometer inside the car says 73.1F, which matches the Tesla app's temp gauge.

Temps seem to be off when the car is in direct sunlight. This is why I asked if anyone knows where the thermocouplers are located in the Tesla.

 

[JohnQ]

The dashboard temperature display is for OUTSIDE, right? It was at 99F when my weather app said 89F (I also verified that with accuweather.com). That was 10F off. When I drove around for 15 min, dashboard temp went down to 93F. I actually didn't open the door when I peeked in to look at the thermometer I placed inside on the seat (out of sunlight though). My test thermometer is calibrated.

Right now, everything is spot on. Dashboard temp says 61F, which matches my yahoo weather app on my phone. The calibrated thermometer inside the car says 73.1F, which matches the Tesla app's temp gauge.

Temps seem to be off when the car is in direct sunlight. This is why I asked if anyone knows where the thermocouplers are located in the Tesla.

This is true of any "thermometer" since radiative heating from the sun will heat the device above ambient air temperature. If it's in the shade, or if there's sufficient air flow, then you'll get an accurate reading. Unless you build a white box around the sensor with a fan to move the air you'll have to live with the discrepancy. It's not a weather station, after all.

 

[skilly]

This is true of any "thermometer" since radiative heating from the sun will heat the device above ambient air temperature. If it's in the shade, or if there's sufficient air flow, then you'll get an accurate reading. Unless you build a white box around the sensor with a fan to move the air you'll have to live with the discrepancy. It's not a weather station, after all.

what he said

 

[jive_devil]

The passenger compartment temperature sensor is behind the grill that is just above the 12 volt power socket, below the center arm rest.

The sideways picture in this thread shows it well:
http://www.teslamotorsclub.com/showthread.php/28863-Grill-Below-Arm-Rest

There are two problems with this placement: (1) Vents are often directed toward this grill, and (2) the air duct for the vent on the back of the center console runs below the center console without thermal insulation and the connections leak air.

Actually, on early VINs (such as my own), the thermometer was in the dash. Supposedly, the new (current) location provides a more accurate reading.