Electrostatic interference and frequency modulation interference can easily cause the displayed digits of the electronic ruler to jump. The strong power line of the linear displacement sensor equipment and the signal line of the electronic ruler are separated by a cable trough. The electronic ruler should use a forced grounding bracket, and the electronic ruler housing (the resistance between the end cover screw and the bracket can be measured, which should be less than 1Ω resistance) should be well grounded. The signal line should use a shielded wire, and the shielded wire should be grounded at one end of the electrical box.

When electrostatic interference occurs, the voltage measurement of a general multimeter is very normal, but the displayed digits jump; the phenomenon is the same when the high-frequency device interferes. To verify whether it is electrostatic interference, use a section of linear displacement sensor power line to short-circuit the cover screw of the electronic ruler with a certain metal point on the machine. As long as the short circuit is made, the electrostatic interference will be eliminated immediately. However, high-frequency interference is difficult to eliminate with the above method, and high-frequency interference often occurs in robot arms and frequency converters. It can be verified by stopping the robot arm or frequency converter.