Measuring the thickness of the air layer sandwiched between two glass plates was an application that needed some critical thinking recently
The tolerance on the thickness was important in determining the barrier properties for a glazing application.
The solution to the measurement problem was supplied by Armstrong Optical using a CHR150 and non-contact interferometric sensor from Stil.
The non-contact white-light sensor is able to measure the thickness of transparent films, coatings and varnishes in the range 2-100 microns with an accuracy of <0.01 microns at kilohertz data collection rates.
For thickness levels above 100 microns other sensors are available.
The sensor itself is connected to the CHR150 optoelectronic cabinet by a shielded fibreoptic cable and, since it is unpowered, can be integrated into harsh/hazardous environments with minimal operating risk.
The installation of the sensor onto gantry systems or robot arms means that even large objects and surfaces can be routinely investigated.
This system has been successfully used to measure the thickness of the polymer coating on the inside of cans used to supply fizzy drinks and the thickness of the varnish on car bodies on a production line.
In both applications speed of measurement and non-contact were determinants in the acceptance of this novel technology.
