We continue to have an ongoing argument over how to conduct a linearity test and what is acceptable. 1) for example measurement of an OD with a micrometer. I understand that it is preferable to get parts with a range throughout the tolerance in order to determine the linearity of the gage. Is it acceptable to use master gage blocks to substitute for actual parts. 2) I have been told that we can use a linearity study on a micrometer as a family. I disagree that you can't just pull a micrometer out of a drawer and do a study using gage blocks to determine if the linearity is acceptable. Is not the purpose to determine if the gage is showing wear in particular area of the measurement range.