Within a parameter of a service capability, there is the ability to turn on test accuracy ratio (TAR), or the comparison of the UUT and the reference standard accuracies.
Navigate to a measurement parameter that is configured. To learn more about service capabilities, go here: Service Capabilities. In the Display/Acceptance tab of the parameter, check the box for "Display Test Accuracy Ratio (TAR)". This will allow the TAR to show in the as found/left data form as explained further down. To set the exact ratio that the TAR must be below to pass, also check the box for "Acceptable TAR varies by service level". Note that this does not need to be checked if the TAR should just display.
If the second box is checked, navigate to the Service Preferences tab of the service capability in order to set the desired ratio per service level. Click on the N/A to input the ratio number compared to 1. Click Save. Do the same for as left. Repeat for each service level that needs the TAR activated.
Now the tool accuracy must be set per reference standard. Go to the Asset Manager and find the needed tool. Click the Role tab then the parameter that needs the accuracy set.
Go to the Tool Range tab. Note: if this tab does not exist, please contact support to have someone turn the functionality on for you. Click Add Range/Mode and fill out the necessary information:
- Tool Range/Mode: purely informational and only seen in this screen; describes the mode the standard is in for the set ranges (e.g. AC Voltage)
- Subtitle: purely informational and only seen in this screen; name the range that is being set
- Range Min: lowest reading input in the as found/left data form for the UUT which the to-be-set accuracy applies
- Range Max: highest reading input in the as found/left data form for the UUT which the to-be-set accuracy applies
- Resolution: to learn more, go here: Assign Resolution to Tools
- Uncertainty: value that can be pulled directly into a budget; to learn more, go here: Uncertainty Calculation Formulas
Click OK when complete.
Now the accuracy for the input range must be set. Click the values under the Accuracy column. This opens up a screen that is the same as the one in the product specification set up. Choose the type of accuracy the standard has then input the value. Click OK when complete. Continue to build out additional range accuracies as needed.
Once the new service level with the TAR option(s) is applied to a work item, the accuracy is set for the work item, AND the tool that has the ranges set up is chosen, the below should happen. The 1:1 ratio is showing because the tool applied had a +/-1 F accuracy set and so did the UUT.