Standard for Combination Head and Dial Caliper Gauge

How about asking Mitutoyo?

I suppose one can only check the error. Calibration may not be feasible. You may dig & look in THIS for any buried info.

Certified gauge blocks. Acquire a set. As far as tolerances there should have been a certification sheet with gauge listing what they are. If its missing call the manufacture and have the serial number ready. May cost you to get a duplicate of the certification.

You can't calibrate dial calibers. That is a function of it's gears. Which can't be changed. Like all gears they do wear. All you can do is set zero and check it for tolerance with the gauge blocks. With certification sheet you will be able to see how the tolerances has changed. If too far out then the caliber will need to be replace or sent out and repaired. At that time the caliber will be tested and re-certified and a new certification certificate issued.

I wasn't going to go there. It just muddies already murky water.

Verify may be more correct. But, I don't think it matters much in this case.

If you don't know how to calibrate it, and you don't know what standard to calibrate it to, how do you know that it must be calibrated at all? And why would not the document that requires calibration specify the method or procedure to be used.

When you get that set of gauge blocks, we call 'em Jo blocks here in the USA, that ozzb suggested, be sure to hire someone who will know how to use them, AND how to care for them.

Another hopeless thread. Send the instrument out to a calibration lab.

It sounds like a complete waste of time for you to try to calibrate the thing internally, anyway. You may do more harm than good.

A potential solution may be to perform a gauge R&R study amongst the staff who would use the device. This would determine the variability of the instrument and permit you to make a business decision regarding the variability and if it is tolerable to your process. If it is acceptable then use it, if not, send it out for repair or replace it.

Google gauge R&R or ANOVA, there is a ton of info available on how to do these.

Did you mean Mitutoyo? There are many models (from about $50 to $1,800). You might be able to find a manual here Mitutoyo Manuals

ehow.com has a good procedure for tuning up a set of calipers.

Most calipers have an adjustment along the slider. These should be tight enough to keep the head from rocking, but also loose enough so that the slider slides.