Tenths

[graham-xrf]

Have you ever tried to use a tenths micrometer, or a 1/1000 mm micrometer to measure anything, and discovered you can't repeat the measurement exactly?

My dad was a builder, and probably never used anything other than a tape and a stick-rule, but he told me the only way to be reasonably happy with any measurement was to do it only once! Trying for twice leaves you having to choose, so it forces you into a third, and if that one fails to totally confirm either of the first two, you might not be able to resist a fourth.

Of course, this contradicted his other homily about measure twice and cut once.

 

[pdentrem]

I use a tenths mic every day in making the metal ribbon we produce. If one is ham fisted the number change just by looking at them. Once one gets familiar with the mic then things do get better.