Common Problems and Solutions for Dual 85 Testing of Temperature and Humidity Test Chambers

    This guide summarizes key issues and solutions for temperature & humidity test chambers during dual 85 testing (85℃, 85% RH), focusing on quick troubleshooting and long-term maintenance for operators and customers.

I. Core Issues & Resolution System

Each issue includes root cause, immediate solution, and long-term prevention (except for defect exposure).

1. Failure to Reach 85% RH

Root Cause: Compressor over-dehumidifies—evaporator temperature below dew point (79-80℃) causes condensation, outpacing humidification.

Immediate Solution: Disable compressor; run only heating and humidification to maintain 85℃ and avoid condensation.

Prevention: Regularly calibrate humidifier atomization volume and check evaporator temperature sensor accuracy.

2. Temperature Out-of-Control/Fluctuations

Root Cause: Mainly faulty solid-state relays (keeps heating elements on), plus aging heating tubes or defective temperature sensors.

Immediate Solution: Cut power; inspect circuit with multimeter (relay on-off, heating tube damage, sensor accuracy) and replace faulty parts.

Prevention: 10-15min pre-calibration before testing; replace vulnerable parts (relays, sensors) every 1000 operating hours.

3. Water Marks/Condensation on Products

Root Cause: Residual oil/dust on products, or dense samples blocking air ducts (poor circulation, localized high humidity).

Immediate Solution: Pause test; clean products with anhydrous ethanol, dry, and reposition samples for proper spacing.

Prevention: Establish pre-test cleaning standards; clean air duct filters regularly and optimize sample rack layout.

4. Incorrect Operation Logic

Root Cause: Operator errors—misactivated refrigeration, wrong parameters (fast heating, delayed humidification), or mismatched operation modes.

Immediate Solution: Reset program (disable refrigeration, set 85℃/85% RH, sync humidification with heating).

Prevention: Develop SOPs; new employees must pass operation assessments (including simulated faults).

5. Material/Process Defect Exposure

Root Cause: Extreme environment accelerates aging—e.g., poor heat-resistant EVA film hydrolyzes (yellowing, delamination); leaky electronic packages cause corrosion/short circuits.

Measures: Inspect products post-test, record defects; judge qualification by material standards; optimize processes (e.g., use hydrolysis-resistant EVA, enhance sealant density).