One of Acuity’s existing customers wanted to be able to measure the thickness of a clear and semi-transparent film on-line. The customer wanted to hold an accuracy of better than 1 microns as the film moved on a web at 25 feet a minute. By using the white light confocal chromatic CL4 MG35 probe on a CCS Prima controller the customer was able to hold +/- 0.6 microns of thickness accuracy with the controller set to take 1,000 samples per second and a data point every 0.005″ along the film’s length. The white light confocal unit is able to measure the front face and back face of the film from one side and provide 2 data points. The difference between the 2 data points is the thickness of the film. By setting the Index of Refraction we can provide a very accurate measurement. Also since the 2 data points are in reference to one another the slight vibration and movement of the film does not change the thickness measurement. The added advantage of the white light confocal unit is that it uses a passive probe that does not have any electronics or moving parts so the measurement is much more stable.
If we can answer any of your questions on the white light confocal chromatic systems please call your Acuity sales person or Manufacturer’s Representative.