What are the calibration methods for coating thickness gauges?
What are the calibration methods for coating thickness gauges? There are three main calibration methods for coating thickness gauges, namely system calibration, two-point calibration and iron-based calibration. Under normal circumstances only an iron-based calibration is required to make accurate measurements. When the magnetic properties and surface roughness of the iron base of the instrument and the iron base of the measured object are greatly different, system calibration can be performed to ensure measurement accuracy. Next, we will introduce the calibration method of coating thickness gauge in detail.
(1) Iron-based calibration
The magnetism and surface roughness of the instrument standard base metal should be similar to the magnetism and surface roughness of the base metal of the test piece. In order to ensure the accuracy of the measurement, iron-based calibration can be performed before measuring the test piece.
Calibration method: After the instrument is turned on, first place the probe on the exposed substrate of the test piece for measurement. Measure twice. After the second measurement, hold the probe still and press the "CAL" key, followed by two beeps. Iron-based calibration can be completed. If two beeps are not emitted, it means the operation is incorrect. Repeat the above steps until two beeps are emitted.
(2) Two-point calibration
During the measurement process, if individual measurement values are found to have large deviations, they can be adjusted through the two-point calibration method.
Calibration method: Measure a tested piece with a known thickness as a standard sample. If the displayed value is inconsistent with the real value, you can add or subtract 1 by pressing the "▲" or "▼" keys. Press and hold the "▲" and "▼" keys to perform continuous addition and subtraction until the displayed value is the same as the real value. After calibration is completed, normal measurement can be performed.
Note: The thickness of the tested piece selected during two-point calibration should not be close to the five sample values during system calibration, otherwise the operation will be invalid.
When the calibration of the fifth sample is completed, the screen displays "0000'', and the startup interface is entered as shown in Figure A. The instrument has completed the system calibration process. In the future, the device under test can be directly measured.
Note: These five sample pieces can use the provided standard piece or a sample piece with a known thickness as the standard piece. Sample calibration should be carried out in order from small to large, and there should be a certain difference between adjacent samples.
