water temp gauge symbol

• 2022-02-22

The icon of a water drop sample and the icon of a wavy line are the engine water temperature gauge.

1. Water temperature gauge:

used to indicate the internal cooling water temperature of the engine. It is an important indicator of whether the engine cooling system works normally.

2. What about the water temperature gauge?

The water temperature is from C to h, and C indicates 60 degrees. As soon as the pointer of the water temperature gauge reaches C, it indicates that the water temperature has reached 60 degrees; The temperature indicated by H red grid is 110 degrees. The pointer should always be kept in the middle position. When the pointer enters the red area, the water temperature is too high. If the water temperature is too high for a long time, there will be "boiling", that is, if the engine coolant boils, the water tank will expand and crack, and the engine will be overheated and damaged.

3. Working principle of water temp gauge

A negative temperature coefficient thermistor is installed in the sensor, and its resistance value will decrease with the increase of temperature.When the power switch is turned on, the current forms a circuit from the positive pole of the battery → power switch → resistance R → coil L2 → divided into two circuits (one flows through thermistor 1; the other flows through coil L1) → grounding → negative pole of the battery.When the water temperature is low, the resistance value of the thermistor in the sensor is large, and the current flowing through the coils L1 and L2 is not much different. However, due to the large number of turns of L1 and the strong magnetic field, the armature 3 with pointer will deflect to the left, making the pointer point to the low-temperature scale; When the water temperature increases, the resistance value of thermistor decreases, the shunting effect increases, the current flowing through L1 decreases, the magnetic field force decreases, the armature deflects to the right, and the gauge needle points to the high temperature scale.

4. Water temperature gauge inspection

When checking the electromagnetic temperature sensor and water temperature indicator, remove the wiring on the sensor and measure the resistance between the input terminal of the sensor and the grounding. If the resistance value of thermistor is about 100 Ω at room temperature, it indicates that the sensor is good; In addition, a resistance of 80 ~ 100 Ω is used to replace the sensor for direct grounding. When the power is connected, if the needle of the water temperature indicator is between 60 ℃ ~ 70 ℃, it indicates that the water temperature indicator is in good condition.The instruments on the dashboard of different cars are different, but the conventional instruments of general cars include speedometer, odometer, tachometer, oil pressure gauge, water temperature gauge, fuel gauge, charging gauge, etc. In modern automobile, the automobile instrument also needs a voltage regulator, which is specially used to stabilize the voltage of the instrument power supply and suppress the fluctuation range, so as to ensure the accuracy of the automobile instrument.