Precautions for the use of electrostatic field tester
1. Before measurement, first check whether the power supply is in compliance with the regulations, whether the instrument shell (including the outer shielding tube of the probe) is well grounded, and the test can only be performed after the instrument is reset.
2. The test probe should be prevented from being in a certain spatial position perpendicular to the surface of the charged object to be tested (according to the test distance specified in the instrument instructions), and the change of the test distance will lead to a large test error. In order to avoid spark discharge between the charged object under test and the probe shell, the probe must be placed far away (from the charged object) at the beginning of the measurement, and gradually approach the charged object.
3. When testing the surface potential, the surface of the charged body should be far enough away from the grounding body. If the charged body is in the form of a sheet or film, and the back is close to the grounding body, when the probe moves to the vicinity of the grounding body, there is a danger of space discharge or surface discharge due to the induction concentration of local charges.
4. When the measured part of the charged body is a large flat plate, the measured value is more accurate, but when the measured surface of the charged body has a certain radius of curvature, the measured value is quite different from the actual potential value.
5. The influence of the instrument's own characteristics on the test accuracy should be considered, and regular calibration and calibration should be carried out before use.
6. The shielding depth of the probe has a certain influence on the test accuracy. The inductive electrostatic field tester is essentially a test of a local electric field of the charged body under test, so the interference and influence of the external electric field on the test signal must be minimized. The usual method is to install this type of instrument and its probe in a grounded shielded casing. Obviously, if the outer shielding sleeve of the probe is too deep, the test accuracy of the instrument will be reduced, and if it is too shallow, it will be easily affected by the external electric field.
7. The value obtained by testing the surface potential of the object can be used as a qualitative reference. It is difficult to achieve accurate measurement in actual work due to various factors.
8. Generally, the electrostatic voltmeter used in the electronics industry should consider the test accuracy, and should be able to test the electrostatic voltage of ±10v.