This question is prompted by another round-robin type study involving the calibration of thread plug gages, the results of which were predictable because similar studies over the past twenty years or so have produced similar results.
During the past 25 years, coordinate measuring machine (CMM) sensor technology has expanded from tactile and scanning systems to now include optical, laser and surface finish sensors, effectively expanding the CMM’s capabilities.
Traditionally, materials testing has been conducted with a device attached to the specimen’s surface to measure the strain. These devices, called extensometers, use very accurate strain gages inside or optical scales.