Theodore D. Doiron, Eric S. Stanfield, Dennis S. Everett
When a force is exerted on any material, the material deforms. Most of the time the effect is small and is neglected. In the measurement of gauge blocks, where the uncertainty goal is stated in nanometers, the deformation is a very large effect, and can be the largest component of uncertainty in calibration by mechanical comparison. We will present the results of a number of studies of the contact deformation of gauge blocks, which shows agreement with the results of calculations based on the work of Puttock and Thwaite. We will also discuss why the use of corrections based on the calculations are not practical in practice, and present a new method for finding the corrections for any comparator, in situ, by using specially prepared set of gauge blocks to calibrate the comparator scale.
Proceedings of 2002 Measurement Science Conference