# Vernier caliper readings (a poem)

• posted on August 19, 2004, 12:57 pm
Learning process:
Years ago I bought a nice Vernier caliper made by Catic in China. Made of a very hard stainless steel. As far as I can tell it matches-up to the graph of figure 3 on this webpage: http://www.rit.edu/~uphysics/uncertainties/Uncertaintiespart1.html "A complete vernier caliper". I am glad for this and glad I found this page. I never figured how to read it beyond the most basics, as well I have no real education because of ADHD and two other brain imbalances, not pleasant for me, 39yo.
I love old classic woodworking tools such as handplanes and chisels and saws. I bought an antique plane blade and cap-iron assembly (\$8, yes tapered and laminated) and decided to measure the blade's width. I am sure the Ohio Tool Co. meant for this blade to be 2 1/2 inches but the reading says less* than 2" and 3/40's plus 17. The 17 is the closest match-up on the "-Vernier scale, does this mean that the measurement is 2.417 inches? Exact scale in text:
2" + 2(8/40) + 4(8/40) (/40) + less than 3/40 and 17 is match-up on the "-Vernier. or 2"-2-4-less than 3/40 + 17 = 2.417"?
Metric: 6.2cm + less than 3mm m-Vernier match-up is 31 = 6.231cm, or 62.31 mm, 6.321? (Metric seems simpler! Big discovery!)
So now I used the software to compare, result as shown:
2.417" = 61.3918mm
62.31mm = 2.45314960629921" 6.231cm = 2.45314960629921"
6.2.31cm = 2.44094488188976" (defunct and kaput)
How do you like that beeswax, ay? Or did I get my decimels in the wrong places?
Many thanks all, Alex
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• posted on August 19, 2004, 2:08 pm
AArDvarK wrote:

If I understand you, it would be 2" + .075 (3/40) + .017 = 2.092
The 17

You lost me here
+ less than 3/40 and 17

Instead of referring to x/40, why not just use .025"? 1/40 = .025" I used to use a vernier all the time, but now everything is digital. A nice compromise (money wise) is a dial caliper. It's just too damned easy to misread a vernier. And yes, metric is much easier....                         Mark L.
http://phoenix.phys.clemson.edu/tutorials/measure /