#### Use TRAX Calibration check box

When calibrating an analog probe on some machine types, particularly when using the Leitz interface, there is typically a choice of whether or not to use the TRAX calibration algorithm for calculating the calibration coefficients. You can choose which calibration algorithm is used by selecting or clearing the Use TRAX Calibration check box. Previously, this setting was controlled in the PC-DMIS Settings Editor by modifying the DISABLETRAXCAL option.

- If you select this check box, PC-DMIS uses the TRAX calibration algorithm. The TRAX algorithm is optimized for use with scanning, so you get the best scanning results using this method. It also usually produces good results for discrete point measurements as well.

- If you clear this check box, PC-DMIS uses the PMM calibration algorithm. In some cases the PMM algorithm may yield higher accuracy for single point measurements.

The selected algorithm only applies to the currently selected tips at the time of calibration. You can change this option later for different groupings of tips as needed. The type of algorithm you chose can also be stored and recalled using named parameter sets. See the "Parameter Sets area" topic in the PC-DMIS CMM documentation.

Note that this check box does not change the distribution of hits that will be collected. Instead, it defines the math algorithm used to process the data after the discrete hit-based analog probe calibration process finishes.

When to use TRAX or PMM

Generally, you can stick with the TRAX algorithm since it works best for scanning and well enough for most single point measurements; but if you must measure single points requiring very small tolerances, you may want to use the PMM algorithm instead.

Note: If you're unsure about when to switch calibration algorithms, you should consult with the creators of your particular machine. They can recommend the best practice for that machine and for particular situations.