How does a car measure the outside temperature at speed, without it skewing for windchill or engine/surface heat?

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How does a car measure the outside temperature at speed, without it skewing for windchill or engine/surface heat?

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Anonymous 0 Comments

temperature sensors don’t measure wind chill. Wind chill is what you feel due to the wind blowing away your body heat. The ambient temperature sensor is located at the front of the car in front of the radiator and the condenser. As long as the car is moving forward it is getting fresh air. At low speeds at at stops, the radiator fan turns on drawing fresh air across it.

Anonymous 0 Comments

Windchill is the effect of a warmer body losing heat to the colder air moving over it.
If you see “feels like XX temperature” that is also a similar reading of Windchill. The wind chill temperatures are included because it’s important for warm things, like the humans reading it planning what jacket to take with them or knowing how long they can be outside without their extremities freezing. Wind will not make a *dry* thermometer any colder than ambient temperature.

Thermometers have no internal heat source to be warmer than the ambient air, and as such have no issues with wind chill. They just equalize to the temperate of the air.

Anonymous 0 Comments

The temperature sensor is typically installed either in the front bumper or in the side view mirror. Either location provides some protection from wind/airspeed effects and is out of the way from the engine. You may notice that after you get your car washed that the temperature drops for a bit and that’s due to evaporative cooling on the temperature sensor..

Anonymous 0 Comments

Thou the wind is moving faster, and feels cooler to the touch, it’s not a different temperature.

The cooler/warmer feeling from touching things like metals or moving air at ambient temperature is due to the faster transfer of heat.

The thermometer will still be able to accurately measure the temperature of the air, even more quickly, while the air is moving.

Actually, having the car not moving is more likely to provide a less accurate temperature reading. The air staying stagnant in the area of the thermometer could be heated by the pavement or engine. If the air isn’t moving, that warmer air is sticking around a while.

Anonymous 0 Comments

Windchill is a mammal thing, we are hotter than our environment most of the time and do things like sweat to cool off. Thermometers don’t. The car actually needs the temperature to calculate the air density, which is important to put the right amount of gas in the cylinder. That’s why the onboard computer has a temperature sensor in the shade of the air plenum, showing the driver is a no-cost bonus feature.

Anonymous 0 Comments

Heated objects such as people, vehicles and buildings maintain a set temperature. Wind increases convective heat transfer, the heater in the people, vehicles and buildings need to work harder as wind increases to maintain the set point temperature.

They place the sensor a for a vehicle a few inches in front of the radiator and calibrate it for that location. Wind is blowing on the sensor prior to cooling the radiator.

Anonymous 0 Comments

I think the other replies are too complex. Let me try:

“Windchill factor” is just a made up way to show people how cold it would “Feel” vs the actual temp. It’s not actually that temperature, it’s just an estimation of how it would “feel” like to you.

Example: It’s -10f, but windchill -22f. It’s not actually -22f. It’s -10f. But when the wind blows and it hits you, it makes your body lose heat so quickly that it would be like if you were actually in -22f cold but the wind standing still. The heat loss would be similar. Hence, it “feels” like -22f even though it’s -10f.

A thermometer is already at whatever temperature the ambient temp is. You are not. Even in -10f weather, your internal core still has to be at 97-98ish. It would be catastrophic for your body to lose even 50f, let alone get to the -10f. Exposed body parts would get frostbite.

The themometer does not. It will simply read whatever the actual temp is.

As far as engine heat, The actual sensor is probably in the trunk, or away from the main engine heat.

Anonymous 0 Comments

Thermometer is placed away from heat source as engine or the car skin that may be heated by the sun, same for car internal thermometer that is generally close to your legs away from the sun, must also be away from air conditioning outlets (disturbs the readings). Thermometer placement is very important for it to function properly.

Once the car moves the airflow will just cool/heat the thermometer faster meaning the instrument will react quicker to change in air temperature.

A thermometer probe aka sensing element MUST be the same temperature of what you want to measure. So “windchill” is actually making it work more accurately as it helps it to stay precisely at the same temperature as the air.

High end air conditioning thermometers do include a tiny fan that blows air onto the sensor to make it faster in perceiving air temperature changes. Other thermometers for air conditioning do have a sensor element that is made like a long spiral wire in the open to achieve high speed of temp change. This does allow your system to keep a good temperature in the room. A thermometer that is not fast in change will make the Air conditioning flipping the room too cold, then finally sensing it, making the room too hot, then sensing it, and so on. Typical “crappy” AC is the one that keeps going off and on full power instead of keeping a little steady and fine tuned flow. And a thermometer that feels the changes quickly is a fundamental factor.

This to say that wind blowing on it is a good thing.

Anonymous 0 Comments

The temperature sensor is placed somewhere far enough from engine or car interior, but internally to shield from wind — like tucked inside of bumper.

Anonymous 0 Comments

They don’t very well, the ones on planes have to be adjusted for speed because the friction of air hitting it while moving warms it up above ambient temperature

The best bet would probably be placing it in the shade away from the sun on the lower side, away from hot components and placing it somewhere with only incidental amounts of air movement. Alternatively there could be a tube designed to capture no air movement at all regardless of vehicle speed – that then turns on a fan blowing through the tube at a known speed while measuring