Effects and Uncertainties Associated With Indirect Measurements of Points on Rigid Bodies

Abstract

Acommon item in the “metrology toolkit” is indirect, or inferred, measurement. Vector bars, hidden-point rods, T-Probes, and B-Probes are all examples of tools that use indirect measurements. The practice is to accurately measure all critical features of a rigid body and record those measurements as a baseline against which subsequent measurements can be compared. Later, when some of those critical features are hidden, the visible features are measured, and the location of the hidden features can be inferred. Indirect measurement techniques are used on a daily basis by many metrology teams, as frequently there is no alternative.