Principle of water temperature sensor:

The water temperature sensor is an important part of the automobile engine control system, which can convert the temperature into an electrical signal and transmit it to the automobile engine control module. When the water temperature rises, the water expands, and the specific heat capacity of water is larger, resulting in larger resistance of the water temperature sensor. This resistance change is detected by the engine control module, which controls parameters such as fuel injection and ignition timing. At the same time, the water temperature sensor can also detect the temperature of the antifreeze, helping the driver to understand the working condition of the engine and the working status of the cooling system.
In short, the working principle of the water temperature sensor is based on the thermal expansion and cold contraction characteristics of water. When the water temperature rises, the water expansion causes the resistance of the water temperature sensor to become larger, and the resistance change is detected by the engine control module, thus controlling the working state of the engine.
The water level sensor in the container transmits the felt water level signal to the controller, and the computer in the controller compares the measured water level signal with the set signal to obtain the deviation, and then issues the "open" and "close" instructions to the water supply electric valve according to the nature of the deviation to ensure that the container reaches the set water level. After the water intake procedure is completed, the computer in the temperature control part issues an "open" command to the electric valve that supplies the heat medium, so the system begins to heat the water in the container. To set the temperature. The controller issued the command to close the valve, cut off the heat source, and the system entered the heat preservation state. In the process of programming, to ensure that the system does not reach the safe water level, the electric regulator of the control heat source does not open the valve, so as to avoid heat loss and accidents.
The water temperature and water level sensor is composed of a temperature controller part and a water level control part, and it is matched with a decompression device in front of the electric valve and a rotary muffler heater for heating. The car water temperature sensor is installed on the water jacket of the engine block or cylinder head and is in direct contact with the coolant to measure the coolant temperature of the engine. The temperature sensor used in the coolant thermometer is a negative temperature coefficient thermistor (NTC), whose resistance decreases as the temperature increases, with a wire connected to the ECU. The other one is a lap wire