Common faults and detection methods of sensor instruments

Guangzhou Zhongxin：

Common issues with sensors

In the use of sensors, we will encounter various problems.

There are many reasons for sensor failures, but in summary, they can be divided into internal and external reasons. The internal cause is mainly caused by faults in the sensor itself, such as aging of internal components and deformation of the elastomer.

External reasons are caused by some human or natural factors, such as sensor overload, impact, or accidental drop, strong pulling of sensor wires, lightning strikes or high current passing through the sensor, chemical corrosion, moisture erosion, or high dust environment.

Common faults and firmware detection methods

Fault phenomenon 1: Data drift and instability

1. Is the mechanical installation part touching

2. The cable is damp (water enters the junction box) (it can be dried with a hair dryer)

3. Poor or damaged cable wiring (re wiring)

4. Sensor insulation impedance decrease (< 200MΩ) (use a multimeter to measure the color wire, shielding wire, and sensor surface separately)

5. The surface of the sensor is charged (measured with a multimeter and resolved through system grounding)

6. Poor system grounding (induced voltage can make the sensor or instrument casing live)

7. Is the instrument casing grounded (not grounded can cause induced voltage to exist)

8. Whether the power supply is stable (whether there is voltage on the ground wire) (Do not share the power supply system with high-power equipment, as voltage on the zero line can cause surface electrification of the instrument)

9. Internal circuit failure (faulty soldering, poor contact of circuit components)
　
Fault phenomenon 2: Incorrect data (too large or too small)

1. Whether the mechanical installation and limit parts touch

2. There is angular deviation (with repeatability)

3. Poor foundation can lead to angular deviation

4. Zero point running: Sensor no-load output>+ 2mV or< 0mV

5. Installation torque/foundation reasons

6. Sensor failure (sensitivity)

Common faults and instrument debugging methods

Negative or zero value of the instrument: The sensor wiring is incorrect.

Solution: It is necessary to check the wiring method, rewire, and reset to zero for calibration.

The instrument value is unstable: the installation method is incorrect, the sensor is faulty, and the instrument graduation value is set too low.

Solution: 1) Calibrate to zero; 2) Increase the indexing value of the instrument, which can be adjusted from 1 to 100; 3) Set the Y value of the instrument to 6000.