1. Zero-point drift
Symptom: Output signal deviates from the baseline value in a static state (e.g., no-load current of a 4-20mA sensor > ±0.2mA).
Reason: Deformation of the sealing ring, tilted installation, or abnormal stress transmission due to temperature changes.
Solution: Replace with a high-temperature resistant sealing ring (e.g., fluororubber), and use a laser level to calibrate the mounting surface (angle deviation < 0.5°).
2. Electromagnetic interference
Symptom: Signal superimposed with power frequency noise (fluctuation > ±0.5mA).
Reason: Signal lines are laid parallel to frequency converter cables or the shielding layer grounding fails.
Solution: Run the signal lines through galvanized steel pipes and ground both ends, and add a copper shielding cover (attenuation ≥ 30dB).
3. Installation stress interference
Symptom: Sensitivity decreases by 20%-30%, linearity < 85%.
Reason: Uneven bolt torque or insufficient flatness of the base (roughness Ra > 3.2μm).
Solution: Gradually increase the torque in steps (6N·m → 12N·m), and grind the mounting surface to Ra ≤ 1.6μm.
4. Excessive temperature drift
Symptom: Zero-point offset > 0.5%FS for every 10℃ increase in temperature.
Reason: Charge output type not selected for high-temperature environment or PCB compensation circuit failure.
Solution: Switch to a charge output model resistant to 150℃ (e.g., ST5484E-121 series).
5. Electrostatic discharge damage
Symptom: Wheatstone bridge open circuit, output signal returns to zero.
Reason: Human body electrostatic discharge (>5000V) breaks down the sensing element.
Solution: Wear an anti-static wrist strap before operation, and select a Class 3B protection level sensor (ESD resistance ≥ 8000V). Other considerations:
Frequency response mismatch: The sensor's frequency range must cover the vibration being measured (e.g., rolling bearing faults require a high-frequency response >10kHz).
Signal distortion: This may be caused by damaged internal components or poor wiring, and requires regular calibration.
