This article explains common faults and troubleshooting methods for linear displacement sensors from six aspects:
(sensor)
1. If the electronic ruler is used for a long time, the seal will age and accumulate impurities. Water and oil mixtures will severely affect the contact resistance of the brush, causing the display to fluctuate continuously. At this point, it can be said that the electronic ruler of the linear displacement sensor is damaged and needs to be replaced.
2. A small power supply capacity can lead to various problems, so sufficient capacity is essential. Insufficient capacity can cause the following: melt movement can alter the display and fluctuations of the mold closing electronic ruler, or the mold closing movement can cause fluctuations in the display of the injection electronic ruler, resulting in significant measurement errors. This is more likely to occur if the solenoid valve's drive power is also provided by a linear displacement sensor. In severe cases, a multimeter's voltage setting can even measure the related voltage fluctuations. If this situation is not caused by high-frequency interference, electrostatic interference, or insufficient neutral point, it may be due to an underpowered power supply.
3. FM interference and electrostatic interference can cause the digital display of a linear displacement sensor's ruler to jump. The ruler's signal line should be kept separate from the equipment's power line. The ruler must be grounded, and the ruler's casing must have good contact with the ground. The signal line must be shielded, and one end of the electrical box should be grounded with shielded wire. If there is high-frequency interference, the voltage measured with a multimeter will show normally, but the displayed number will jump continuously; the situation is the same when electrostatic interference occurs. To verify if it is electrostatic interference, you can connect the ruler's cover screw to some metal on the machine using a power cord. As long as a short connection is made, the electrostatic interference will be eliminated immediately. However, it is difficult to eliminate high-frequency interference using the above method. Variable frequency economizers and robotic arms often have high-frequency interference, so you can try stopping the high-frequency economizer or robotic arm to verify if it is high-frequency interference.
4. If the linear displacement sensor's electronic scale periodically skips the displayed data at a certain point during operation, or does not display any data, it is necessary to check whether the insulation of the connecting wire is damaged and whether it periodically touches the machine casing, causing a short circuit to ground.
5. The power supply voltage must be stable; the industrial voltage must meet the requirement of ±0.1%. A 10%V quasi-voltage fluctuation of ±0.01V is permissible. Otherwise, it will cause display trap fluctuations. However, if the displayed fluctuation range does not exceed the fluctuation range of the voltage fluctuation, the electronic ruler is normal.
6. During the connection process, pay close attention to ensure that the three wires of the electronic ruler are connected correctly, and do not replace the power cord and output wire. Incorrect online connections will result in large and difficult-to-control linear errors, decreased control accuracy, and the display may frequently jump around.
