Ortofon applies the Gauge Repeatability and Reproducibility (R&R) when testing the cartridges.
Three operators test ten cartridges of one specific model e.g. 2M Black, SPU Anniversary 90, Cadenza Bronze. The set-up of the test is different for each specific cartridge model.
Acc. to the ASTM E691 Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method, at least ten operators or laboratories have to be involved in the testing in order to capture the reproducibility errors.
As for the measurements of the same cartridges, two or three operators provides a very reliable result. In order to capture the repeatability errors, each operator measures the same cartridge several times.
Each measurement cycle of the individual cartridge includes a set of defined operations, incl. the mounting and dismounting of the cartridge on the tonearm in the measurement system.
Test of the test process
Each of the three Ortofon operators tests each of the ten cartridges three times, meaning that each cartridge is tested nine times by three different skilled operators. Typically an Ortofon operator has more than five years experience and routine in assembling/disaasembling cartridges.
The test of the test system is a part of the industrial production. It is a demanding process, where Ortofon works using the Repeatability and Reproducibility strategy in order to minimize, if not eliminate entirely, the variations in ALL parts of the measurement system.