The performance of the high and low temperature test chamber should be determined under standard atmospheric conditions. When measuring the performance of the test chamber, the surrounding environment may affect the conditions in the test chamber. The following requirements should be considered for the high and low temperature test chamber measurement: 1. The surrounding environmental conditions should basically meet the requirements of GB / T2421. 2. The test box should not be directly exposed to sunlight; 3. The test chamber should not be exposed to electromagnetic interference; 4. The high and low temperature test chamber should be placed horizontally; 5. The test chamber should be placed in a place free from mechanical vibration and acoustic vibration. Note: The test box manufacturer's recommendations for power and environmental conditions should be considered; abnormal conditions should be recorded. Temperature measurement system: The uncertainty of the measurement results of the measurement system is determined by the calibration of the system. Generally speaking, the sensor should be a resistance type or a thermocouple type. The 50% response time of the sensor in the air should be between 10s-40s The response time of the entire system should be less than 40s. Temperature sensor installation: temperature measurement sensors are located at each corner of the test chamber and the center of the working space (at least 9 sensors). For high and low temperature test chambers above 2000L, the sensors should be placed directly in front of the center of each wall (at least 15) Sensors), the placement of the measurement system should not affect the temperature distribution of the no-load test chamber, and should be able to record the actual temperature reached. Temperature performance determination: After the test chamber is stabilized, the actual temperature, temperature fluctuation and temperature gradient of the working space are confirmed according to the measurement results of the measurement system, and the uncertainty of the temperature measurement system should be considered. Sichuan Soper Science & Technilogy Co., Ltd , https://www.Soper.com.cn
Test load of high and low temperature test chamber: All the following measurements are made in an empty working space. If the test chamber cannot be completely empty, it should be recorded. For the measurement when there is a load (heat dissipation or no heat dissipation), it should be recorded. Whether the tested sample in the box has heat generation, weight, quantity, placement density and arrangement order have an effect.
Key points for measuring the five performances of high and low temperature test chambers