how does temperature sensors work??

Answer 1

They come in many types and work differently. A sample list follows.

The one with a mechanical gauge on a supermarket meat freezer has a bimetal coil. Two strips of two different metals are bonded together and coiled up. The difference of the two metals’ thermal expansion coefficients causes the coil to move with temperature.

The one in a car engine is either a thermocouple (cheap car) or a RTD (luxury car). A thermocouple has two different metal wires that are resistance welded at their ends. The difference of the two metals' free valence electron potentials (physicists call it the Fermi level) causes a voltage to build up proportional to the temperature.

An RTD (resistance temperature detector) is typically a metal (e.g. platinum) resistor whose resistance changes with temperature. This change of resistor is typically small but well repeatable and is converted to a change in voltage typically by a 4-arm balance-resistor network (electrical engineers call it a Wheatstone bridge). This bridge outputs a voltage that changes with temperature.

Thermistor is another inexpensive way to measure temperature. It starts from Michael Faraday’s 19 century discovery of silver sulphide which has its resistance drop significantly with temperature (NTC, for negative thermal coefficient).

The digital temperature sensors in todays laptop computers count a characteristic frequency of oscillation of a circuit. This frequency is a function of temperature.

Infrared scanning makes another reliable remote temperature sensor especially for higher temperatures. The radiation of heat has a group of wavelengths whose principal one centers around a narrow bell shape distribution of wavelengths whose mean value gets shorter with higher temperature.

Answer 2

thermistor is a type of temperature sensor
there is a resistance whose value gets changed according to the change in temperature, when u put this resisor in a circuit, the current and hence the output voltage changes, there is a caliberation between the voltage and the temperature, and thus the temperature is found

Answer 3

Yes, the CTS will do this. If not working or detecting a lower coolant temp. the engine will run rich. OK for cold starts but a problem for warm starts. Crank and cam sensors do not create or receive spark, only provide information to when the spark should occur. With a scan tool that can read data, the coolant temp can be compared to intake air temp on a cold (not running) engine to see if there the same.

Answer 4

Thermocouples like copper Constantin produce an electric current when sensing temperature. This current can be introduced into a computer or a sensing device and show the temperature in degrees.