Temperature sensors measure the air temperature in the intake manifold of the engine.
Information on air temperature is  necessary for some electronic fuel injection systems, in order to indirectly calculate the quantity of sucked air and then establish the correct dose of petrol. This guarantees low emissions and good engine performance.
Air temperature in the collector is converted by the sensor into a proportional voltage and sent to the engine control unit, which processes it, also taking into account the absolute pressure of the air and the number of engine revolutions.