Interpretation of the operation method of hot and cold shock testing machine

Interpretation of the working mode of the thermal shock test machine

High and low temperature impact test chamber:

Thermal shock test chamber is a necessary testing equipment in materials industry is used to test the structure of material or composite material, and the degree of endurance under continuous environment of extremely high temperature and extremely low in an instant can detect the thermal expansion and contraction of the sample in the shortest time. chemical changes or physical damage. The hot and cold shock test chamber meets the test methods: high and low temperature impact test GB/T2423.1.2, GB/T10592-2008, GJB150.3.

Working principle:

The upper and lower refrigeration cycles adopt the reverse Karol cycle, which consists of two isothermal processes. and two It is composedof an adiabatic process, and the process is as follows: the refrigerant is adiabatically compressed to a higher pressure by the compressor, and the exhaust gas temperature is increased by consuming work, then the refrigerant isothermally shuts down the heat exchange with the surrounding environment through the condenser and transfers heat to the surrounding environment. surrounding media. Once the refrigerant passes through the stop valve, it performs adiabatic contraction and the temperature of the refrigerant decreases. This cycle repeats to achieve the cooling objective.

Technical parameters of hot and cold shock test chamber:

1. Temperature range: -20℃, -40℃, -60℃, -70℃～150℃

2. Temperature fluctuation in sample area: ≤0.5℃

3. Temperature fluctuation in high temperature room and low temperature room: ≤±2℃< /p>

4. Temperature biasre: ≤±2℃

5. Temperature recovery time: ≤5min

6. Low temperature to high temperature conversion time: ≤15s

7. Heating rate: 1~3℃/min

8. Cooling rate: 0.7～1.2℃/min Hot and cold shockK test chamber meets: GJB150.3-86; GJB150.4-86; GJB150.5-86; GB/T2423.1-2008; GB/T2423.2-2008; GB/T10592-2008 and other relevant national standards.

Operation:

Generally speaking, the operation of the upper and lower temperature shock test chamber is divided into five stages: preprocessing, initialization Detect, experiment, recover and finally test.

1. Pretreatment: Place the test sample under normal experimental atmospheric conditions until the temperature is stable.

2. Initial Test: Compare the tested sample with standard requirements. If it meets the requirements, it can be directly placed inthe upper and lower thermal shock test chamber.

3. Experiment:

1) The experimental sample should be placed in the experimental box according to the requirements of the specifications, and the temperature in the experimental box (chamber) should be increased to the specified point, and the experimental sample must be preserved for a certain period. The temperature reaches a stable temperature, whichever is longer.

2) After the high temperature step is completed, transfer the experimental sample to a low temperature experimental box (chamber) that has been adjusted to -55°C within 5 minutes and persist for 1 hour. or until the experimental sample reaches a stable temperature, whichever is longer. Everything will prevail.

3) After the low temperature step is completed, transfer the experimental sample to a high temperature experimental box (chamber) that has been adjusted to70°C within 5 minutes and persist for 1 hour or until the experimental sample reaches a stable temperature. prevail.

4) Repeat the above experimental method to complete three cycles. Depending on the sample size and space size, the time may have a slight error.

4. Recovery: After the test sample is removed from the test box, recovery should be stopped under normal experimental atmospheric conditions until the test sample reaches a stable temperature.

5. Final Inspection: Evaluate the inspection results against the degree of damage stated in the specification and other methods.

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