When we operate the detection of dry film thickness, we generally follow a measurement principle, that is: 90-10 principle or similar detection principles.
The measurement principle of 90-10 mainly means that 90% of the measured values cannot be lower than the specified dry film thickness, and the remaining 10% of the measured values cannot be lower than 90% of the specified film thickness.
For example, if the dry film thickness is specified as 30 microns, then 90% of the measured values must be above 300 µm, and the remaining 10% of the measured values must not be lower than 90% of the specified film thickness of 300 µm, that is, 270 µm. (Related Instruments: Thickness Gauge)