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by Brian on February 29th, 2008
You would use outside calipers for the external diameter and inside calipers for an internal diameter:
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Comments
I just have to say that your avatar is too funny.
by Da Azian Boi on February 29th, 2008
You would not, however, use that design of caliper for measurement at all, ever. It has no scale.
Instead you would use http://www.toolstation.com/images/library/stock/webbig/45921.jpg for small objects, a micrometer screw gauge for smaller ones and probably measure the circumference of large ones and calculate
by Freddy Says remove all moderation points on February 29th, 2008
With the calipers that I've shown one only has to place the tips on a scaled measuring device, such as a ruler.
by Brian on February 29th, 2008
~sighs~
.
So, two sets of measuring errors then.
by Freddy Says remove all moderation points on February 29th, 2008
What measuring errors does a ruler or do the calipers have?
by Brian on February 29th, 2008
With the little problem that a proper caliper as shown in that link (also a micrometer) has flat surfaces and is near impossible to place wrongly on the object. The one shown above is easy to place in a way that is not perpendicular to the object's surface. You have to hit the exact centre of a cylinder on both sides.
by PokkiTokki on February 29th, 2008
I'd be measuring the caliper tips against the object before I placed it against the ruler.
by Brian on February 29th, 2008
measuring errors also transfer to reading the value from the scale (a "ruler" is something that you use to rule lines with. an engineer uses a "scale")
.
You will have parallax errors in reading each caliper tip, and estimating errors in the fractional units you will estimate the tip readings.
by Freddy Says remove all moderation points on February 29th, 2008
Actually I'd be placing the tips tangentially to the objects surface.
by Brian on February 29th, 2008
You would be using the wrong tool whatever you did. But, since you don't seem to listen, please feel free.
by Freddy Says remove all moderation points on February 29th, 2008
and you can do that tangential placing with a precision that let's you measure to 1/10th or 1/100th of a millimeter which is common in metalworks? good luck with that.
by PokkiTokki on February 29th, 2008
The distance between the caliper tips would still be a straight line which is directly applicable to a ruler.
The tips are usually aligned on the two fixed parallel planes so any parallax errors would be to manufacturing errors or user misuse.
by Brian on February 29th, 2008
And, while I understand what you mean by "tangentially", as does PT, I am sure, you MEAN perpendicular. And finding the diameter position is next to impossible with this tool, which is NOT a measuring caliper at all, but is a gauge.
by Freddy Says remove all moderation points on February 29th, 2008
OK. I'm bored now. I have now told you how and why you are incorrect in sufficient ways to show you how incorrect you are. I have given up
by Freddy Says remove all moderation points on February 29th, 2008
"and you can do that tangential placing with a precision that let's you measure to 1/10th or 1/100th of a millimeter which is common in metalworks? good luck with that."
The asker didn't specify that he needed metalwork precision measuring.
by Brian on February 29th, 2008
Brain, how about just learning something? I am not going to teach you any more, though.
by Freddy Says remove all moderation points on February 29th, 2008
Actually I've learned quite a bit.
I'm sure I'll find plenty of other sources for my continued education. ;)
by Brian on February 29th, 2008