Film thickness gauges:
Film thickness gauges | Film thickness chart | Coating thickness conversion | Sound velocity chart
Magnetic and Electromagnetic Induction Gauges
The magnetic induction gauge uses a permanent magnet and a magneto-resistor to detect changes in the magnetic flux. These changes appear when you nears a steel surface. If the thickness of your coating varies then the magnetic flux will change too.
Eddy current sensors can be a good choice when your substrate is conductive but not magnetic. It creates it´s own opposing magnetic field that is sensed by the coil. An Eddy current thickness gauge is used in the same way as an electromagnetic gauge.
Ultrasonic thickness gauge
With an ultrasonic thickness gauge you can measure coatings on non metallic materials, wood and plastics for example. The gauge sends an ultrasonic pulse through the coating which reflects on the substrate.
Wet Film Thickness gauge
This is used when you want to measure wet film thickness of paint, adhesive,
inks and other similar products.
Many times it is important to measure the thickness of the coating when it
is still wet, this to know that the correct thickness is applied during the
process. If the coating is to thick it will eventually crack and waste ink
or paint, and if it's too thin it will not cover properly.
These combs are made from, stainless steel, aluminum or plastic and has
calibrated "teeths" whith different depths on each edge.
Place a comb firmly on the substrate. Hold the comb in position and wait a
few seconds until the notches are "wet". Remove the comb. The wet film
thickness lies between the highest value "wet" notch and the smallest value
"dry" notch value.
Wet film wheel (eccentric roller)
The film wheel uses three disks. By rolling the gauge through a wet coating, the centre disc eventually touches the film. This point on the scale indicates the thickness.