Any driver who has raised an eyebrow when their car’s temperature gauge reads much higher than what it feels like outside have every reason to do so, according to the Bureau of Meteorology (BoM).
Temperature readers, which are typically located on the dash, are an important part of a car’s heating, ventilation and air-conditioning system (HVAC).
“Your car needs to know how hot it is outside in order to cool you down using the least amount of energy possible,” BoM said in a release.
The sensors that retrieve the information are often placed in the front grille or under one of the side mirrors.
If they were placed in certain spots with the intention of avoiding direct contact with sunlight and hot engine parts – how are the gauges unreliable?
Official temperatures readings are taken by BoM by placing a box with louvres over a natural surface like grass to allow the air to circulate while being protected from the sun and rain.
“In your car, on the other hand, the temperature reading can be affected by the surrounding environment. The largest consideration is the heat radiated by the road surface,” BoM says.
“If the temperature sensor is under the wing mirror, it has a front-row seat to the hot bitumen under your wheels.”
Metal panels and heavy traffic can also exacerbate the heat.
“Even with fresh air moving over the sensor as you drive, your sensor can experience 'heat soak' where the sensor and its enclosure become so warm that the time you spend moving is not enough to cool the assembly down sufficiently to get an indicative reading of the ambient temperature,” BoM says.
BoM recommended checking their official observations for the correct temperature.
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