31
Appendix - Calibration Procedures
Instructions for using the Setup File and Calibration
Template.xls
Calibration of the Lasercheck gage involves testing known surfaces with the Lasercheck and developing a
correlation between the Lasercheck readings and the actual Ra roughness values on several surfaces with
different roughness values. This correlation is stored in a setup file that is used when the Lasercheck
performs a measurement.
Lasercheck requires calibrations for different processes. Lasercheck will read a turned surface different than
it reads a lapped and polished surface so an independent calibration is required for each of these processes.
Once a calibration is performed, Lasercheck never requires re-calibration for a given process.
Smooth and Rough Mode
Lasercheck calculates roughness using algorithms optimized for “smooth” or “rough” surfaces. Smooth
algorithms provide most accurate readings on surfaces approximately 10 microinches and smoother, and
rough algorithms provide most accurate readings on surfaces 10 microinches and rougher. The installation
program loads an uncal_s.set (smooth surface algorithms) and uncal_r.set (rough surface algorithms) file on
the C:\Program Files\Lasercheck\Setup Files\Microinches directory. These two setup files must be used for
performing calibration measurements. These files should be loaded on the Lasercheck controller.
Smooth Mode Measurements
Using the “>” button on the control box, scroll until the LCD screen displays:
SELECT>UNCAL_S
^System:
Calibration measurements are taken and saved on test surfaces. If the surface is too rough (typically greater
than 10 to 20 microinches) the Lasercheck system will not display a reading.
Rough Mode Measurements
Using the “>” button on the control box, scroll until the LCD screen displays:
SELECT>UNCAL_R
^System:
Calibration measurements are taken and saved on test surfaces.
Calibration Spreadsheet
The spreadsheet is designed to step you through the calibration process from "Step 1" through "Step 6".
Follow the detailed instructions on each page of the spreadsheet. The overall process involves:
1)
Perform and save measurements on calibration test surfaces with the Lasercheck using uncal_s.set
file. If any test surfaces are “too rough” for uncal_s.set to properly calculate roughness an error
message will be displayed. Repeat and save measurements using uncal_r.set on any surfaces that
provide this error message.
2)
Measure calibration test surfaces with a calibrated stylus gage (if the actual surface roughness is
not known.
3)
After measurements are performed, follow the specific numbered instructions on each sequential
page in the spreadsheet (Step 1 Enter Ra Values, Step 2 Mid Range, Step 3 High Range, Step 4
Low Range, Step 5 Review, and Step 6 Export Setup File).
