(Brunson: Kansas City, MO) -- Every day, laser tracker operators risk their accuracy by using their SMR (spherically mounted retroreflector) targets with worn and damaged target holders (nests). Over the course of time, wear and tear on a target nest takes its toll, and undetected error creeps into your measurements. The instrument accuracy you paid for isn’t what you achieve.

Target holder accuracy can deteriorate by worn surface treatments or coatings, corrosion on interior or exterior nest surfaces, damage from dropping, or even repeated surface contact from rough tooling. When nest wear or damage places the SMR target outside the original spec tolerance, your assumption of accuracy is no longer valid.

Some companies maintain a calibration lab onsite and regularly verify target nests’ dimensional tolerances. Stock is rotated from production to calibration and back. Out-of-spec nests are replaced with new. While effective, this is a high-cost approach.

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