#### Material Coefficient boxes

The Material Coefficient boxes contain numbers reflecting the material property, and are the fractional change in length per unit change in temperature.

- Values vary depending on what type of material was used to make the scales on the machine axes and on what the part is made of.

- Units are per degree C or per degree F, depending on the selection of the check box for displaying in Celsius or not.

- This can be thought of as meters/meter/degree C or inches/inch/degree F but since the length in both the numerator and denominator are in the same units they divide out.

Example: A scale with a coefficient of 11.5 microns /meter/degree C becomes 0.0000115 meters/meter/degree C or just 0.0000115/degree C.

Qual Tool Coefficient

This box allows you to specify the material coefficient for the probe qualification tool separately from the part.

Acceptable Part Values on Leitz Machines

In versions v42 MR2, v43 MR1 and later, if you are using a Leitz machine, PC-DMIS will force you to use an acceptable material coefficient value in the Part box. An acceptable value lies within the range of -.0001 through 0.001 Meters/Degrees Celsius (or -0.00056 through .00056 Inch/Degrees Fahrenheit).

- If you enter a value outside this acceptable range in the Temperature Compensation Setup dialog box, a warning message will appear and the value in the Part box will be reset to 0.0.

- If you open a part program created from an older version of PC-DMIS that permitted unacceptable values, a message box will now inform you of the unexpected material coefficient value and PC-DMIS will reset the value to 0.0.

- If you attempt to manually edit the TEMPCOMP/ORIGIN command to use an unacceptable value, PC-DMIS will display an error message within the Execution Mode Options dialog box during execution. The message will inform you that the Part material coefficient value is out of range. The only option is to click Cancel and modify the command to contain an acceptable value.