9 replies to this topic

[Bluemini]

One for you engineering boffins...

I just got a new set of vernier callipers (Rabone Chesterman), on the main body is the measurements in cm and inches, but on the sliding bit there is also a set of markings. On the cm side they are almost the same size as each mm going up to 20, but in comparrison to the main measuring part, they fall short of 2cm by 1mm. On the inch side there are markings again on the sliding bit in whatever scale they are in going up to 25, the 20 mark falls short of the 1" on the main body by a 32th of an inch. At the end of the main measurements it says 1/1000 inch on the inch side and on the cm side it says 1/20 mm.

Confused? Me too!

[miniman5]

uhhh............................................................................
........................


use a hammer

[Ade]

The measurments on the slidey bit are sub millimeter (hence the 1/20mm) Has been a while since I used old ones (got myself a set of digital ones as they're idiot proof!! :nugget: ) and I can't for the life of me remember exactly how you tell the sub mm reading on the old ones :grin:

So overall not a lot of use really :tongue:

[Ade]

Tis something like when you have closed them around the object to be measured the line on the slidey part that is closest to lining up with a mark on the main shaft is the measurement and how many points of a mill past is that makes sense (it doesn't to me when I read it) I need to see an old set and it'll all come flooding back... :nugget:

I am standing by to be corrected though :tongue:

[Ade]

Alternativley ignore all my rambleing and have a look at this

http://www.phy.ntnu....er/vernier.html

[Ade]

I was kinda right though in a gibberish kind of way :nugget: :grin:

[mattvallins]

Yeah, the line on the slider nearest to linibg up with the millimetre mark is the exact measurement.

[Bluemini]

I can't see that link because I don't have whatever program it uses

[bluebottle]

if its the same as a micrometer (which i think it is), on the imperial scale the little marks are in 25 thou increments..........we dont use that new fangled metric stuff very much in my job, so i'm not sure what increments they would be in.

[Bluemini]

I've sussed it now, the inches are like you said in 25 thou increments and the mm are in 20 (whatever mm are measured in) increments. Which ever mark it lines up with tells you how far thru the mm it is, eg. 0.5 of a mm is 10 on the scale because its half of 20, 15 = 3/4 etc. But inches puzzle me, they make no sense with all those crazy fractions.