I am not an MSA guru. I am not familier with Type 1 or Type 2 testing. In my company we do, however, have the issue of automatic versus manual gages (or measurement systems). In the case of automatice gages, our practice is that the operator is not a variable (as the tool is automated, the operator plays no part in measurement variation). So repeatability is done the same way whether manual or automatice. But reproducibility on automatic eqiupment is not between operators, but between shifts or days or equipment shut downs. Rather than multiple operators, the reproducibility portion would include sets of measurements taken on different shifts, or different times of day, etc.

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I have not heard of type 1, type 2 in reference to GRR studies. The MSA manual specifically states that reproducibility is variation in the average measurements made by different appraisers. It also states there are some measurement systems where the reproducibility is considered negligible.We have interpreted this by doing a GRR study with one appraiser (a GR study if you will)for our automated equip. It kind of makes sense but I can't help that.

I am currently using R&R studies recommended in the MSA manual for both automatic and manual gauges. However I have recently been told that I should be using Type 1 studies for automatic gauges and type 2 for manual gauges. The MSA manual makes no refrence to this, can anyone shed any light on the subject?

Thanks

Rob Nicholl

Yes, with "automatic" measurement equipment you usually only determine repeatability.

However, be sure there is no operator influence available. If the "automatic" device requires different operators to "fixture" parts - as in a laser micrometer, CMM or Vision type system, or the operators must set-up and standardize a device prior to measuring parts, it should be considered that there are other potential sources of variation.