Measuring Nominal Points

While locating an instrument by fitting to a set of nominal points (see “Best Fit Points to Points”) is not a difficult task, you may find that using “Measure Nominal Points” is preferable for typical in-process alignments.

Measuring nominal points offers some notable benefits over Best-Fit:

There are a few things to keep in mind when using this command:

The best fit by measure nominals dialog is shown below:

Initial Settings .The upper portion of the dialog offers basic configuration controls that should be considered before beginning the measurement process.

Measurement Controls. On the right-hand side of the dialog are a set of measurement controls used primarily for direct instrument control. Measurements do not need to be triggered from this section if you are measuring directly but they offer greater automation if needed.

Tolerance. You can specify a tolerance in this field. Any deviation magnitudes that exceed the tolerance will be highlighted red. Click the Apply button to apply the specified tolerance to the table.

Point List.  The point list field is used both to display which points have been measured and to control the measurement sequence. Points do not need to be measured in order. After the first 3 points have been measured, and assuming you have the Closest Point check box enabled, the point associations are detected automatically. However, you can also change this order by selecting a particular point from the list and measuring it directly.

Standard workflow To Locate an Instrument by Measuring Nominals

  1. Ensure the instrument interface is running.

  2. From the menu, select Best-Fit > Measure Nominal Points.

  3. If more than one instrument exists in the file, select the instrument to transform, as prompted.

  4. Select the nominal (reference) points. The Locate Instrument by Measuring Nominals dialog is displayed.

  5. In the Group to Contain Measured Points section, type in a name for the point group in which to place the measured points.

  6. Measure points manually or automatically using the dialog as described above. Once three or more points have been measured, click the Finished -- Locate Instrument button at any time to accept the fit and complete the command.