Heating and cooling rate of constant temperature and humidity test chamber

The heating and cooling rate measurement of the constant temperature and humidity chamber needs to be carried out under full load conditions, and the heating and cooling rate: the average change rate per 5min is 5±1 °C/min or the average change rate
of the test chamber is high.
The test point is the center point
of the workspace geometry.
Constant temperature and humidity chamber heating and cooling rate test procedure: within the adjustable range of the temperature of the test chamber, select the low nominal temperature as the low cooling temperature and the high nominal temperature as the high heating temperature
.
Turn on the cold source, so that the test chamber is reduced from room temperature to low cooling temperature, at least 3h stable, rise to high heating temperature, at least 3h after stabilization, and then drop to zui low cooling temperature
.
During heating and cooling, record 1 time per minute until the end of
the test process.
Calculation and evaluation of test results: the measured temperature value is corrected according to the correction value of the test instrument; The temperature is calculated according to the formula of GB11158 clause 5.
5.
4.
2, and the rate of change should meet the requirements of
clause 4.
1.
7.
Inspection and evaluation method of sealing performance of refrigeration system: use halogen lamp or soapy water to check the sealing condition of the pipe joint of the refrigeration system, if there is no leakage, it meets the requirements of
Article 4.
2.
3 。 Test and evaluation method of thermal insulation performance: This test is carried out during the heating and cooling test, when the test chamber reaches the high test temperature and stabilizes for 3h, use a surface thermometer to check the temperature of the outer wall of the test chamber, the observation window frame and other easily accessible parts, such as not higher than 50 °C, under low temperature conditions, when the ambient temperature is 30~35 °C, the relative humidity is 75%~85%, there should be no obvious condensation phenomenon
on the outer wall, door and seal of the box 。 When the test chamber reaches a low test temperature and stabilizes for 3h, observe the condensation on the outer wall of the box and the seal of the door with the naked eye, such as no obvious dew drops or water film
.