To avoid confusion on the left is a dial indicator, on the right is a dial test indicator (DTI):
![test gauges.jpg test gauges.jpg](data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==)
The dial indicator is intended to make precise measurements with the plunger moving axially. Using it to indicate while applying a side load is inaccurate.
If the greater movement of a dial indicator is needed to centre work in a lathe chuck then the technique being used is wrong. One can get well within 0.5mm by aligning the jaws on the chuck with the concentric rings on the chuck body, or by eye against a lathe tool. Or just note where the DTI touches and where it doesn't and adjust according. Then fine tune position using the DTI; I normally aim for less than 0.02mm total runout. I only use a DTI for aligning parts in the lathe chuck. I find it to be fast and accurate, given the correct technique.
Andrew
PS: I acknowledge MikeK beating me to it ![smile smile](data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==)
Edited By Andrew Johnston on 24/03/2022 16:15:54