When you start a new file, it will default back to no scaling option. Make sure you change it back to "none" if you wish to not use this option as the software will continue to compensate for this materal and temperature if you do not.
You can manually adjust for a materials thermal expansion in either CAM Measure 4.0 or X. In the software go to:
Review Features > Highlight Device Position > Click Edit > Select Material Temperature.
Insert your material temperature and then you can select your material from the drop down provided. If your material is not listed then you can manually insert you coefficient of linear expansion in terms of celsius.
The temperature does not need to be set for probe calibration. There are temperature sensors in the arm that will compensate for the contraction/expansion of the arm. The arm will always measure the part at its actual size regardless of the temperature (in the 10 to 40 C range of the arm). The temperature compensation in Measure is used to address the contraction/expansion of the part since it will measure larger than design if it's hot and smaller than design if it is cold.
Temperature compensation for measurements should be set in the Device Position (if used). It is also part of the Alignment process, but doesn't work as effectively if you have multiple Move Device commands. If you set the temperature to 2000 C and measure a 20 mm hole it will modify the XYZ location and shrink the diameter by a factor of the expansion coefficient and the temperature difference (2000 C to 20 C). It should not affect the CAD model, only the measurements and constructions. If the temperature compensation is changing the CAD then it's a bug. The nominal data should never change.
Temperature compensation should be used when the part is very large and the tolerances are tight (i.e. most laser tracker applications). With a FaroArm the temperature probably won't affect the part enough to make much of a difference.
Keywords: adjust temperature compensation, material compensation, thermal expansion