Room temperature tube temperature sensor: The room temperature sensor is used to measure the indoor and outdoor ambient temperature, and the tube temperature sensor is used to measure the wall temperature of the evaporator and condenser. The room temperature sensor and the tube temperature sensor have different shapes, but the temperature characteristics are basically the same. According to the temperature characteristics, there are two types of room temperature tube temperature sensors used in the United States: 1. The constant B value is 4100K±3%, and the reference resistance is 25°C corresponding to the resistance 10KΩ±3%. The higher the temperature, the smaller the resistance; the lower the temperature, the greater the resistance. The farther away from 25°C, the larger the corresponding resistance tolerance range; the corresponding resistance tolerance at 0°C and 55°C is about ±7%; and below 0°C and above 55°C, the resistance tolerance will be different for different suppliers. . The higher the temperature, the smaller the resistance; the lower the temperature, the greater the resistance. The farther away from 25 °C, the larger the corresponding resistance tolerance range.