Calibrating Micrometers

[Twud]

If the the anvils are touching and thimble reads 0 is your micrometer necessarily calibrated?

 

[Preacher]

It would be to its self but not necessarily to any other......

 

[chino1969]

If the the anvils are touching and thimble reads 0 is your micrometer necessarily calibrated?

You need a set of standards to properly check your calibration. A 1" micrometer standard is not terribly expensive and is a good thing to have if you are concerned about accuracy and verifying your measuring tools.
Chino69

 

[Link]

Why couldn't you make a comparator by measuring a item with 2 micrometes and see if they measure the same?
We used precision ground blocks at work.

Link

 

[RickB]

What Chino69 said. If you want to be certain, get the calibration set. They should be traceable to a national standard. That way whatever measurements you get are more likely to be close to those of someone else calibrating their instruments in a similar manner. Temperature is one factor that can make a difference, both in terms of the calibration and the temperature that either the instrument or the object being measured may pick up either in being handled or otherwise.

 

[DaveBrokos]

I use a ceramic gauge .250. Ceramic is pretty much impervious
to temperature. They are not cheap but you can rely on it to set your micrometers.

 

[RickB]

I use a ceramic gauge .250. Ceramic is pretty much impervious
to temperature. They are not cheap but you can rely on it to set your micrometers.

Dave,

Thanks very much for the tip. I had not thought about a ceramic gauge, but it is almost the perfect material for this use.

Cheers,

Rick