Mechanical Micrometer Calibration and Measurement Accuracy - Metrology Training Lab

In episode 012 of the Metrology Training Lab, we'll explain the accuracy and micrometer calibration of mechanical outside micrometers. You may be surprised to find out the accuracy of a mechanical micrometer with a graduation of 0.001” is one-tenth of that.
To calibrate micrometers, and trying to decide if they are in or out of tolerance, there is another very powerful trick you need to know. *This works for Mitutoyo micrometers. The width of the scale lines on the sleeve and thimble are specifically designed to help you make higher accuracy measurements without having to read between the lines. Watch the video to find out how.
#metrology #calibration #micrometer #mitutoyo

[@sonumandlik5185]

Plz make video on bore dial gauge.

[@brucewilliams6292]

This was very informative! Thank you.

[@MitutoyoAmerica]

Glad it was helpful!

[@terrywilder9]

@@MitutoyoAmerica Here's a trick worth noting to estimate between graduation marks to get an extra order of precision: The human eye will recognize small whole fractions between these marks, the recognition of which decreases as the denominator increases. For example if you have an indication that appears to divide adjacent graduations/intervals into three equal parts this recognition will pop right out, so use/record 0.33 or 0.67, not 0.3, or 0.7, respectively; or you could have an indication that divides adjacent graduations/intervals into four equal parts use/record 0.25, 0.50 or 0.75 not 0.2 (or 0.3), 0.5 or 0.7 or 8. Then round as necessary.

[@jillbluerei4806]

Can you use feeler guages to verify the accuracy of a ball micrometer?

[@elanjacobs1]

This is why I prefer mechanical mics over digital. If the lines are fine enough, you can even split the vernier scale to read half microns/tenths.

[@gazzzada]

Measurement accuracy is not a function of resolution, no matter between lines or digital. There are resolution requirements in accuracy classification but repeatability, reproducibility and bias are major contributors in any measurements including linear ones.

[@TheOne8017]

I didn't need a history lesson on micrometers. I came to this video for the exact thing that it was titled, calibration. This video showed nothing about how to calibrate a micrometer.

[@samtzam3774]

If someone take a measurement by guessing (aka higher than the resolution). He/She have to write it down on the recording. So if the meas is 2.2505" and the resolution of the instrument is .001" the record must be written as 2.2505"±.001". Just to give the information of the uncertainty that the record of the measurement has.

[@dr.jimsalsbury695]

In my opinion, the more important point is to understand the difference between resolution and the scale interval (or graduation). As shown in this video, a micrometer with 0.001" graduations has a resolution 10 times smaller than that (maybe more).

[@MF175mp]

@@dr.jimsalsbury695 great to see the man himself replying to comments.

[@havefunbesafe]

Question for anybody; how does a surface plate work in the world of calibration of tooling like micrometers, dial indicators, etc…I’m new to this stuff and wondering why a flat surface plate is needed for anything?!?? Pardon my ignorance on this subject. Thanks.

[@MitutoyoAmerica]

For more information on Surface Plates, please check out this video kzbin.info/www/bejne/ooi3dHSCbpl1adk

[@petermoses5095]

i would not waste time with electronic mikes . i have had so many errors with mikes and verniers .