Amphenol Advanced Sensors’ OAT sensor measures the temperature outside the passenger compartment and is usually mounted inside or near the front bumper or in the side mirror. The sensor relays the outside air temperature to the controller of the automatic HVAC systems. The controller uses this temperature to help control the interior temperature of the vehicle. The sensor also provides the vehicle occupants with temperature readings from outside the car. This information is particularly useful when driving under near freezing or freezing conditions.