Air conditioning temperature sensor temperature probe Room temperature & tube temperature

1. The resistance of different types of temperature sensor is different, but how to judge the quality of the temperature sensor? Very simple, it is to measure its voltage online, the normal voltage at 25 degrees is generally between + 2 ~ + 2.5V .

2. Because the human body temperature is constant, the on-circuit voltage is not constant (approximately 2.17V) when holding the temperature-sensing head for a while.

3. Unplug the temperature-sensing head, and measure the resistance of the two pins of the socket on the line. The resistance value is basically the model value of the temperature-sensing head at 25 ℃ (this method is inaccurate after actual inspection). If the resistance is about 8K, the model value of the sensor temperature head is generally 10K; if it is a 4.7K resistance, it is a 5K temperature head; and so on. However, for some large air conditioners, the resistance value of the temperature sensor of the control board of the inverter air conditioner external unit is 3 times the lower bias resistance, that is, the resistance value measured by the above method multiplied by 3 is the resistance value of the sensor at 25 ° C.

4. The model value of the temperature sensor is its resistance value at 25 ℃, usually 5K, 10K, 15K, 20K, 50K, which are generally negative temperature coefficient, that is, the higher the temperature, the more the resistance value small.

5. Generally speaking, the temperature of the internal machine tube and the room temperature resistance are the same.