1、 Abnormal measurement parameters
Abnormal temperature display
Fault phenomenon: The temperature display shows 0 ℃ or abnormally high temperature (such as 274 ℃).
Diagnostic steps:
Check if the connection between the PT100 temperature sensor and the circuit board is loose, loose, or misconnected.
Use a multimeter to measure the resistance value of PT100, and determine whether the sensor is damaged by using the formula actual temperature=(measured resistance value -100)/0.385. If the calculated value deviates significantly from the actual temperature, the sensor needs to be replaced.
Enter the device settings menu and confirm that the temperature input mode (PT100 or thermocouple TC) is consistent with the on-site configuration.
Abnormal flow rate/pressure data
Fault symptoms: Flow rate or pressure displayed as 0, full range or large data fluctuations.
Diagnostic steps:
Check if the pitot tube is blocked: if it is blocked, use a wire with a diameter of ≤ 5mm to clear it; If there is partial blockage, use a high-pressure blowback air source (pressure ≥ 0.35MPa) to blow multiple times.
Confirm whether the values of the differential pressure transmitter and pressure transmitter are normal, and investigate whether the pipeline is loose or the solenoid valve is leaking.
Check if there is a "differential pressure abnormal" prompt on the device status interface. If the sensor cable is loose, it needs to be unplugged again.
2、 The device cannot start or black screen
power failure
Diagnostic steps:
Check whether the 220V power supply line is open, short circuited or has poor contact, confirm that the power switch is turned on and the fuse is not blown.
If the power supply is normal but the screen is black, use a multimeter to test whether the 24V switch power supply inside the device has output. If there is no output, the switch power supply needs to be replaced.
hardware failure
Diagnostic steps:
If both the power supply and switch power supply are normal, but the device does not respond, it may be due to a damaged circuit board. Contact the manufacturer to replace the circuit board, do not disassemble it by yourself.
3、 Data transmission failed
Communication line issues
Diagnostic steps:
Check if the communication cables are damaged, loose, or interfered with, reconnect or replace the cables.
Confirm that the communication parameters (baud rate, data format, address) between the device and the upper computer are consistent, and modify any mismatched parameters.
Equipment failure
Diagnostic steps:
If the communication parameters are correct but the data cannot be transmitted, it may be due to a damaged communication module. Contact the manufacturer for repair or module replacement.
4、 Backblowing and calibration failure
Insufficient blowback pressure
Diagnostic steps:
Check if the pressure of the blowback air source is ≥ 0.35MPa. If the pressure is too low, adjust the air source pressure to 0.35-0.6MPa.
If the pressure is normal but the blowback fails, it may be due to a damaged blowback pressure sensor and the sensor needs to be replaced.
Zero calibration failed
Diagnostic steps:
Confirm that the device is in a stable environment and avoid interference from vibration or temperature changes.
If manual calibration fails, try the automatic calibration function; If it still fails, it may be a sensor malfunction and the sensor needs to be replaced.
5、 Daily maintenance suggestions
Regular calibration: Perform manual or automatic zero calibration every 3-6 months to eliminate zero drift.
Cleaning and maintenance: Clean the pitot tube monthly with a high-pressure blowback air source to prevent particle accumulation; Check the connecting hose quarterly for looseness or dust accumulation.
Environmental monitoring: Ensure that the installation environment temperature of the equipment is between -25 ℃ and 65 ℃, and avoid high temperature or corrosive gas damage to the sensor.
Tip: If the fault cannot be eliminated through the above steps, it is recommended to contact the equipment manufacturer or professional maintenance personnel to avoid secondary damage caused by improper operation.