High-low temperature chamber performance measurement method

High-low temperature chamber performance measurement method

The performance measurement method of high and low temperature test chamber is divided into 5 points:

1. Environment in the test area: The environment surrounding the high-low temperature test box can affect the conditions inside the test box. The determination of the performance of the test box should be conducted under standard atmospheric conditions. The following requirements should be considered: The surrounding conditions of use should not be directly Exposure to sunlight, exposure to electromagnetic interference, horizontal placement, rotation in areas not affected by mechanical vibrations and sound and vibration should be taken into consideration by test chamber manufacturers on electricity and environmental conditions. The "site confirmation letter" issued by Taifeng Branch is the mainstay.

2. Temperature measurement system: The uncertainty of the measurement result of the measurement system is determined by the calibration of the system. Generally, the sensor should be of the resistance type or the thermocouple type. The 50% response time of the sensor in the air should be within 10s-40s. Between the entire system response time should be less than 40s .

3 , the test load of high and low temperature test chamber: we will have a note in all technical information (the following technical indicators are measured under no-load conditions), if the test chamber can not be empty, it should be recorded, the box was Whether or not the sample has heat, weight, quantity, placement density, and order of arrangement are all affected.

4 , the installation of temperature sensors: temperature measurement sensor is located in each corner of the test chamber and the center of the work space, our industry has nine factory inspection instrument inspection standards, so the box should be at least 9 sensors, for the high temperature above 2000L The test chamber should be installed in front of the center of each box wall (taking into account the large space in the box, in order to achieve an accurate uniformity, at least 15 sensors should be placed in the box ), and the deployment of the measurement system should not be Influencing the temperature distribution of an empty test chamber should be able to record the actual temperature of arrival. For the confirmation test system, data should be recorded at least once per minute. The data recording device of the test chamber monitoring sensor should be independent of the test chamber control system.

5. Temperature performance measurement: After the test box is stable, the actual temperature, temperature fluctuation and temperature gradient of the working space are confirmed based on the measurement results of the measurement system, and the uncertainty of the temperature measurement system should be considered.

Attachment: In order to determine the rate of temperature change, the chamber should be adjusted to the minimum specified temperature or the chamber should be adjusted to the maximum specified temperature. The temperature should be monitored from the 10% temperature point to the 90% temperature point to stabilize the test chamber. , Adjust the test chamber to the minimum specified temperature, and monitor the temperature from the temperature range of 90% to 10% . This is the temperature rise and fall speed we often say (here we take the entire average), According to the user's requirements, the linear temperature rise and fall can be set to 1-20 degrees /min (the term "slope" in the instrument setting).