Definition - What does Calibration Shim mean?
A calibration shim is a small thin color-coded strip of material generally made of plastic. They are used to check the calibration of digital coating thickness gauges. Certified shims are available in various thicknesses from 2 microns to 12,500 microns (~0.07 mils to ~ 490 mils).
Calibration shims provide a method to accurately measure the performance of a coating thickness gauge for the user.
Calibration shims are also known as calibration foils.
Corrosionpedia explains Calibration Shim
Calibration shims or foils are a thin material (plastic or metal) used to accurately measure the calibration of a coating thickness gauge. Usually they are used for calibrating Type II (fixed probe) magnetic dry film thickness gauges within tolerance and to ensure that the user is following the correct procedure for gauge operation.
Calibration shims provide the most accurate way to create a standard coating thickness on the substrate material, surface finish or form. They are available either as a precision foil (±1% accuracy) or as a nominal foil (±2% accuracy).
Calibration shims can be a single piece or laminated in layers. Laminated calibration shims are available in sets of 5 uncertified shims, or 8 certified shims in a rigid folder. They are used at construction sites and in laboratories.
Plastic shims are an alternative to metal shims. They are not as accurate as metal shims, but are cost-effective. Certified plastic shims are used to protect probes from damage or wear when used with abrasives or on hot surfaces. They can also be used with Type 2 electronic gauges for coating thickness standards.