Understanding of the equipment used for this and the ways to use it very important to make a correct judgment. There are many different types of gauges, which use various principles to carry out this measurement. Determining factors are different type of coating, the substrate material, the thickness range of the coating, the size and shape of the part, and the cost of the equipment that you need.

The paint thickness gauge is most commonly used in the automotive industry to measure the thickness of the paint of the automobiles. It’s like having an extra pair of eyes with X-ray visions to analyze and form a judgment about the paint job of the cars. It’s a second opinion that you would have always longed for when you go ahead to buy a car. The paint of cars can be very delusional to the naked eye. It can look different at different angles and type of lighting. A gauge on the other hand is not mislead by the lighting, it is a powerful tool for looking for evidence of accidents or any paint repairs including patching of the rust spots. It’s a reliable and quantifiable way of determining the quality of paint. The paint thickness gauge is also very useful for the detailers, refinishers and quality control during the manufacturing process of the car. It works by determining the depth of the coat of the paint and that too in a non-destructive way. The concept behind the paint gauge can vary, some use magnets while others electrical currents. The ones which use magnets are basically for the ferrous backings like steel, while fiberglass and plastics use ultrasound as way of calibrating.

‘Magnetic pull off’ paint thickness gauges are simple and inexpensive. They are also light and portable and thickness of the paint is analyzed by determining the pull-off force. The coats of paint which are thick will have lesser magnetic attraction than the ones which are thinner in comparison. They can be pencil like or with rollback dial models. On the other hand the electronic device measure the change in the magnetic flux density at the surface magnetic probe as it comes close to a steel surface. By the value of this magnetic flux density the thickness of the paint coating is found out. For the ultrasonic gauges, ultrasonic pulse-echo technique is used to measure the thickness of paint on plastic, wood or any other non-metal surfaces. The ultrasonic transducer of the instrument sends a pulse through the coating. This pulse is then reflected back and is converted into high frequency electrical signal and is then analyzed to determine the coating thickness.

The paint thickness gauge should be carefully stored in protective cases when not in use as they are carefully calibrated. Also they should be sent for re-calibration as and when needed.