# Caliper Accuracy



## Thread man (Jul 17, 2022)

There often seems to be varying opinions on how accurate a caliper is. There is a standard for how a standard caliper should be made and how accurate it should be. The standard to which almost all calipers (vernier, dial and digital) are manufactured is DIN862. This is also the standard to which calipers are normally calibrated to at authorized calibration facilities. There is both an ISO and ASME standard almost identical to DIN862 but DIN862 was first. An interesting fact is that the correct or recommended measurement force (N) is not given in any standard but will of course vary depending on caliper length. As far as I know the recommended force (N) in standards is given as "suitable".

Of the 3 types (vernier, dial and digital) vernier is the least accurate. Dial and digital are equally accurate but digital are available in many more lengths. Digital also have several advantages over the other two and probably the most important is that by simply pushing a button they can switch between metric and inch. This also means thaat the caliper manfacturer doesn't have to think about what system the user uses.

As already mentioned there is no “standard” for what a correct measurement force (N) is and the word most often used is “suitable”.

Caliper accuracy.



			https://flexiblemeasuring.com/wp-content/uploads/pdf/digital_caliper_accuracy.pdf
		


I personally prefer digital so this video only shows digital calipers.



Several “experts” say that the greatest cause of inaccuracy when using a caliper is the user. I must admit, based on years of experience, I tend to agree.

N.B. The correct way to change from mm to inches is to divide mm by 25.4.


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