To set Part Compensation parameters for the active measure

To adjust your measurements for the effects of comparing the part to its mold and for the effects of thermal expansion:

1. Click Measure tab > Current panel > Parameters.
2. In the Measure Parameters dialog, select the Part Compensation tab.

Note: Part compensation is available only when creating inspections for CNC and Manual machines.

To compensate for comparing the part to its mold:

1. Enter the multiplier by which you want to scale measurements in the Shrinkage factor box. For example:
   • If you do not want to allow for shrinkage, enter a multiplier of 1.
   • If you are comparing a part with a model of the mold, and the shrinkage is 3%, enter a multiplier of 1.03.
   • If you are comparing a mold with a model of the part, and the shrinkage is 1.5%, enter a multiplier of 0.985.
2. Select Save as default parameters if you want to use these values as the defaults for new inspections.
3. Click OK to save your changes.

To compensate for thermal expansion of the part:

1. Select Set temperature automatically when taking first measurement to use the temperature recorded by the measuring device when you click Play All. Deselect the check box to manually specify the temperature for each Measure.

   If you select this check box and the machine protocol does not support automatic temperature measurement, an error message is displayed when you start the inspection.

2. Enter the Thermal expansion coefficient of the part:
   • To use a standard coefficient of expansion, select the part's material in the drop-down list.
   • To specify the coefficient of expansion, select Custom in the drop-down list, and type the coefficient in the box.
   • To disable thermal compensation, select None.
3. Select Save as default parameters if you want to use these values as the defaults for new inspections.
4. Click OK to save your changes.

Note: PowerInspect does not compensate for thermal expansion of the probe head and stylus. If you need to compensate for these changes, calibrate your measuring device at the temperature at which the measurements will be made.

Specifying the part temperature at the start of an inspection

The Part Compensation dialog enables you to specify the part temperature immediately before measuring all unmeasured items in the inspection sequence.

To specify the part temperature at the start of an inspection:

1. In the Part Compensation tab of the Measure Parameters dialog:
   1. Deselect the Set temperature automatically when taking first measurement check box.
   2. Specify a standard or Custom coefficient of thermal expansion greater than zero.
2. Click OK to close the dialog and save your changes.
3. Click Measure tab > Manual panel > Play All.

   The Part Compensation dialog is displayed with the name of the active Measure shown in the Active Measures list.

4. In the Temperature box, enter the temperature of the part in degrees Celsius and press the Tab key. PowerInspect calculates the measurement compensation factor from the Thermal expansion coefficient and displays it in the Scaling factor box.
5. Click OK to save your changes and close the dialog. PowerInspect switches to full-screen mode and displays the Feature Probing dialog for the first unmeasured item.