What should I do if the high and low temperature test chamber has problems?

High and low temperature test chamber may encounter a variety of problems in the process of use, the following is a summary of potential faults and their causes from different perspectives:

1. Core system failure

Temperature out of control

Reason: PID control parameters are out of balance, ambient temperature exceeds the design range of the equipment, multi-zone temperature interference.

Case: In a special environment workshop, the external high temperature causes the refrigeration system to overload, resulting in temperature drift.

Humidity is abnormal

Reason: poor water quality of humidification leads to scaling and nozzle blockage, failure of ultrasonic humidifier piezoelectric sheet, and incomplete regeneration of dehumidification desiccant.

Special phenomenon: reverse condensation occurs during high humidity test, resulting in the actual humidity in the box being lower than the set value.

2. Mechanical and structural problems

Air flow is disorganized

Performance: There is a temperature gradient of more than 3℃ in the sample area.

Root cause: the customized sample rack changed the original design air duct and the accumulation of dirt on the centrifugal fan blade led to the destruction of dynamic balance.

 sealing failure

New failure: the magnetic force of electromagnetic sealing door decreases at low temperature, and the silicone sealing strip becomes brittle and cracks after-70℃.

3. Electrical and control system

Intelligent control failure

Software level: After firmware upgrade, the temperature dead zone setting error occurs and the historical data overflow causes the program to crash.

Hardware level: SSR solid state relay breakdown causes continuous heating and bus communication is subjected to inverter electromagnetic interference.

Security protection vulnerabilities

Hidden dangers: the synchronous failure of the triple temperature protection relay and the false alarm caused by the expiration of the refrigerant detector calibration.

4. Challenges of special working conditions

Specific temperature shock

Problem: -40℃ to +150℃ rapid conversion of the evaporator weld stress cracking, thermal expansion coefficient difference resulting in the failure of the observation window seal.

Long-term operation attenuation

Performance degradation: after 2000 hours of continuous operation, the compressor valve plate wear leads to a decrease of 15% in refrigeration capacity and drift of ceramic heating tube resistance value.

5. Environmental and maintenance impact

Infrastructure adaptation

Case: The power oscillation of PTC heater caused by the fluctuation of power supply voltage and the water hammer effect of cooling water system damaged the plate heat exchanger.

Preventive maintenance blind spots

Lesson: Ignoring the positive pressure of the box leads to water entering the bearing chamber and biofilm growth and blockage in the condensate discharge pipe.

6. Pain points of emerging technologies

New refrigerant application

Challenges: system oil compatibility problems after R448A replaces R404A, and high pressure sealing problems of subcritical CO₂ refrigeration systems.

IoT integration risks

Fault: The remote control protocol is maliciously attacked, resulting in program tampering and cloud storage failure, resulting in the loss of test evidence chain.

Strategy recommendations

Intelligent diagnosis: configure vibration analyzer to predict the failure of compressor bearing, and use infrared thermal imager to scan the electrical connection points regularly.

Reliability design: key components such as evaporator are made of SUS316L stainless steel to improve corrosion resistance, and redundant temperature control modules are added to the control system.

Maintenance innovation: implement a dynamic maintenance plan based on operating hours, and establish an annual refrigerant purity testing system。

The solutions to these problems need to be analyzed in combination with the specific model of the equipment, the use environment and the maintenance history. It is recommended to establish a collaborative maintenance mechanism including the OEM of the equipment, third-party testing institutions and user technical teams. For key test items, it is recommended to configure a dual-machine hot standby system to ensure the continuity of testing.