Digital Multimeter is measuring not only Voltage values but also Current and Electrical resistance. If it is so, how can we conduct study on it? Does it mean that we have to conduct separately as in, one for Voltage, one for Current, and one for Resistance? Moreover, can anyone tell me how can I gather data for Current Meter? For resistance, we have resistors... for current and voltage, how?

In analogy, is it correct to say that we can conduct GR&R only to equipment who has standards that are fixed and have known values like for example Caliper to Gauge Blocks?

Thanks in advance...

Hfamous:

Well.. I think that you should do GRR on all 3 modes of the multimeter, if you are using those modes in your process.

Your samples that you use for GRR should be representative samples from your process. For example if you use your multimeter to measure leak current of an electronic device, take a sample from your electronic device.

My advice would be not to use lab. standards, if at all possible. Your GRR should represent as close as possible the actual process.

Kales is correct. You should perform a separate study for each mode of measurement that you use. You should also use actual product, not standards. If the parameter to be measured fluctuates or drifts it will impact the measurement just like variation in form will affect a dimensional measurement. Unfortunately that is the reality that you must deal with.

I recommend performing a stability study to identify whether this is an issue.

One thing is clear, which everyone also agrees upon. A separate study needs to be done on each scale of measurement offered by the multimeter. Not just separate studies for the parameters, but also for separate scales within the same parameter.

Secondly, GRR is not calibration. So, comparison with lab standards is not the purpose. What we need to check is the consistency of the reading, whether right or wrong. So, for conducting the study, we need to know that the current being measured is not fluctuating while the study is being conducted. Not knowing the exact measurement of the current is perrfectly OK.

Not just separate studies for the parameters, but also for separate scales within the same parameter.

Excellent observation and exactly correct. The different scales typically have different resolutions, and the manufacturer's usually base the stated "accuracy" (whatever they mean by that) as a percent of the scale.

Thanks for the response! In Filipino language... "Salamat po!" :-)