.2mm pro using 5mm pro setting point and Gauss Filter.

[[Ri...]]

 7.500 OD , but 5.0mm pro will hit the 11.500 OD. 

0.2mm pro will fit well, But can I use 500 Gauss Filter and 4250 points on 0.2mm pro to measure 7.500 OD. 

[[Ch...]]

Depending on which probe head you are using (VAST XXT or VAST) the technical minimum stylus diameter is specified at 0.3mm, see below. You can still use a 0.2mm and I suspect you won't have any issues but it may be in your best interest to measure a ring gage after qualification just to ensure it is measuring accurately.