1. Testing instruments

Oven, thermal resistance thermometer, crinkled masking tape, LED overalls indicating conduction

2. Inspection method

1. Use corrugated tape to fix the temperature sensor head of the RTD thermometer tightly to the temperature sensor surface of the thermostat. Be sure to wrap the temperature sensor head of the RTD thermometer with multiple layers of corrugated tape to prevent the temperature sensor head from being exposed to the external temperature environment, so that the temperature sensed by the temperature sensor head of the thermometer and the temperature sensor chip inside the thermostat are similar.

2. Connect the two side pins of the thermostat to the LED work clothes.

3. Place a piece of waste cardboard on the oven's fixing bracket and place the thermostat on the paper block (avoid the thermostat and the temperature sensor head of the thermometer directly touching the oven's metal fixing bracket and inner cavity). Close the oven and turn on the heater.

4. When the temperature in the oven reaches: the temperature switch position temperature -20℃, lower the temperature of the oven by 3 to 5℃ every time (when the temperature in the oven reaches the set temperature, lower the temperature of the oven by 3 to 5℃. Because the ovens in most factories cannot control the rate of temperature drop, it is possible to prevent the temperature from rushing straight up).

5. Until the temperature of the oven reaches the lower limit of the thermostat action temperature. At this temperature, let the oven temperature stabilize for more than ten minutes. Observe whether the thermostat is working. If the thermostat is working, it is NG; if the thermostat is not working, continue to test below.

6. Set the oven temperature to decrease by 1 to 2℃ and check if the thermostat is working. Raise the oven temperature to the limit temperature of the thermostat working temperature. At this temperature, let the oven temperature stabilize for more than 10 minutes and check if the thermostat is working. If the thermostat is working, it is OK; if the thermostat is not working, it is NG.