Acuity has had a request from a customer that would like to be able to measure the thickness of their glass plate and also the air gap between the dual pane glass panels. The customer used the white light confocal probes from Acuity to be able to measure the thickness of the glass panel from each side and perform a differential calculation to provide the air gap between the glass panes to a few microns in accuracy.
The customer used 2 Initial white light chromatic CL5 MG35 probes. The CL5 MG35 probe has a standoff of 29 mm with a measurement span of 12 mm. The probe has a resolution of 400 nanometers and a linearity of +/- 800 nanometers. The white light technology is very unique in that the spot size remains a constant size of 14 microns in diameter and can measure on any surface including measuring through clear surfaces. By setting 2 probes up facing each other the customer can measure the front surface of each side of the glass to provide an overall thickness. The probes can also measure through the glass panes to measure the position of the back face of each glass pane. By performing a simple subtraction we can then calculate the air gaps thickness. The Initial controller has the capability to use the index of refraction of the material to provide an accurate measurement of the targets.
The Initial also outputs in both USB and RS232 digital signals to make the calculation easily and the customer can use a control loop to provide real time control of the manufacturing process.
Acuity has many probe size available with measurement ranges between 70 microns up to 24 mm for many applications.
If you have difficult targets that need to be measured and scanned accurately the white light confocal chromatic technology provide a very good result for your application.