In the sample weighing process of pharmaceuticals, food testing, environmental monitoring and other fields, a constant temperature and humidity weighing room can provide a stable temperature and humidity environment to ensure the accuracy of weighing results. The constant temperature and humidity weighing room may experience various malfunctions due to environmental factors, component wear, or improper operation during long-term use. The following are common problems and corresponding solutions.
Common faults and solutions of constant temperature and humidity weighing room:
1、 Abnormal temperature and humidity control
1. The temperature cannot reach the set value
Fault manifestation: Slow or stagnant heating/cooling, deviation between actual value and set value>5 ℃.
Possible reasons:
•The heating tube is damaged or has poor contact (abnormal resistance value).
•Refrigerant leakage (high pressure gauge pressure<6Bar).
•Circulating fan malfunction (blade deformation or motor burnout).
Solution:
•Use a multimeter to check the resistance of the heating tube and replace damaged parts.
•Contact professional personnel for leak detection, fluorine replenishment, and compressor maintenance.
•Clean up the dust accumulation in the air duct and replace the faulty fan.
2. Abnormal humidity display
Fault manifestation: Continuous high/low humidity, failure of humidification/dehumidification function.
Possible reasons:
•Humidifier electrode scaling or water level sensor malfunction.
•The condensation pipe of the dehumidification system freezes or the drainage pump is blocked.
Solution:
•Soak the humidifier electrode in citric acid solution to remove scale and clean the water level float.
•Stop the machine and thaw the condenser pipe, and clear the drainage pipe.
2、 Equipment operation interruption
1. Frequent start stop of compressor
Fault manifestation: The compressor stops after running for 10 seconds and repeats the cycle.
Possible reasons:
•The condenser is dirty and blocked, causing a high pressure alarm.
•Refrigerant leakage (low pressure<0.1MPa).
Solution:
•Clean the condenser fins, repair the leaks, and then vacuum and fill with fluorine.
•Check the lubricating oil level of the compressor and replace the bearings if necessary.
2. Sudden power outage or error message
Fault manifestation: The screen is black or displaying codes such as "Overload".
Possible reasons:
•Power supply voltage fluctuation (<340V) or three-phase power phase loss.
•Control board capacitor bulges or relay burns out.
Solution:
•Install a voltage regulator (≥ 50kVA) and check the phase sequence of the power cord.
•Export fault logs and replace damaged electrical components.
3、 Abnormal data collection
1. Missing temperature and humidity records
Fault manifestation: Data breakpoint or deviation from set value>2 ℃/5% RH.
Possible reasons:
•The sensor is damp or aged (output signal drift).
•Loose communication cables or oxidized interfaces.
Solution:
•Dry or replace the sensor, recalibrate.
•Check the RS485/Ethernet interface and tighten the wiring terminals.
2. Display screen garbled code
Fault manifestation: Character confusion or white screen.
Possible reasons:
•The power fuse is blown or the control board chip is overheated.
Solution:
•Replace the fuse with the same specifications and check the cooling fan.
4、 Environmental factors have an impact
Poor heat dissipation: The equipment is placed against the wall (recommended distance>30cm) or the condenser accumulates dust.
•Poor sealing: air leakage at the door gap (smoke test can be used) or aging of the sealing strip.