On Monday, 20 May 1996, thomas walter x5955 wrote:
> Cool blue skies, nice breeze, and a desire to "goof off" for
> part of the day. Couldn't resist, fired up the '67 2000...
Nice brutal little British sports car, made in Japan. I'd love to have
one for autocrossing.
> Also he had a 14" vanier caliper
Vernier. Named for Pierre Vernier, who came up with the concept of the
vernier scale in around 1766, I think. Hey, we Frenchmen have to look
out for one another...
The vernier caliper, with a direct-reading scale attached to one jaw,
and a vernier scale attached to the other, has been in common use since
abut 1876. In the English system of measurement, a vernier allows one to
read a caliper to .001 inches.
The vernier scale is also used on micrometers in order to read to .0001
inches, or one "tenth" as machinists call it.
> my use is limited for them, but I couldn't pass it up
> at $40... new is over $400.
You bet. I would probably hurt my arm reaching for my wallet to get a
14" vernier caliber for $40. You will never get hurt on that one.
> Oh... I brought along some "standards" with me.
You bought gauge blocks to look at used tools? Good idea. Like bringing
your all luggage with you when you buy a road car...
> All checked OK.
And it will stay that way, too. Dial calipers are another matter.
One should check the entire travel on a dial caliper with blocks because
the mechanism is prone to problems from chips and such. I had an
instructor who would not allow a dial caliper in the shop. He kept one
in his tool box to show. I zeroed perfectly, and read .025 off at 3 inches.
> I was wondering how much would a 14" vanier caliper
> vary over temperature (stainless steel)?
If your part is the same temperature as your caliper, and the temperature
at which your spec book calls for the part to be measured, you are not
going to have a problem. If the difference in expansion coefficients is
going to give you a hard time on your tolerances, you need more
sophisticated equipment in the first place.
Phil Ethier <ethier@freenet.msp.mn.us>
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