Drift Check is an essential tool to verify that an instrument has not been bumped or physically moved in any way, ensuring measurement accuracy. It can easily be accessed by directly right-clicking on the instrument you want to check.
It is a good practice to perform a drift check at the end of each measurement task, multiple times during a long measurement job, and any time that you suspect the instrument may have moved in any way.
The Drift Check dialog may appear familiar. The group name control and measurement controls are the same as those used in the Measure Nominal Points alignment, and in many ways it’s the same operation. It allows you to select a set of points and measure them in a fast and efficient manner. In fact if you choose to Add a new instrument and align, the Measure Nominal Points dialog will open for you automatically for greater control over the alignment.
However, the advantage of Drift Check is that it provides both a report of the current deviations and a preview of the RMS and Max deviation you would see if you were to re-fit, aligning using a Best-Fit to the nominal points. This is quite helpful because the deviations can be compared, and an informed decision can be made as far as how to proceed.