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Misterg
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I think it's called a dioptometer - for measuring the 'power' of lenses.
Basically just measures curvature (like a radius gauge), but calibrated for the refractive index of glass (that's what I believe the 'n= 1.523' refers to).
I guess that you'd take a reading from each surface of the lens and add them together to get the refracting power of the lens in dioptres. (A dioptre = 1/(focal length in metres) )
Basically just measures curvature (like a radius gauge), but calibrated for the refractive index of glass (that's what I believe the 'n= 1.523' refers to).
I guess that you'd take a reading from each surface of the lens and add them together to get the refracting power of the lens in dioptres. (A dioptre = 1/(focal length in metres) )
Misterg
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It's a 'Lens Clock' apparently:
That's what it does, but the gauge is calibrated to the optical power of the surface under test, assuming a refractive idex of 1.523
(What I would call a spherometer has 3 contact points in a ring around the gauge probe, but that's by-the-by.)
Base Curve Measure 1.53
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That's what it does, but the gauge is calibrated to the optical power of the surface under test, assuming a refractive idex of 1.523
(What I would call a spherometer has 3 contact points in a ring around the gauge probe, but that's by-the-by.)
Agroshield
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The one in the link shows 20 (not sure if it is plus or minus 20) in its relaxed state. Fizzy's one shows -1. Could his one be gummed up?
I am guessing zero is with all three points co-linear.
The German one increases anticlockwise; the linked one increases clockwise.
Well spotted - a quick squirt of WD40 and it is back on zero. The bezel doesn't turn or anything like on a dti.
Perhaps I could turn it into the worlds most useless watch - it looks cool though
Agroshield
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It might have an engineering use. Look at 'radius of curvature' in the Wiki page:
Lens clock - Wikipedia
If you applied it to an ISO mugforscale, does it give a meaningful result?
Misterg
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Yes, zero should be with the probe and points against a flat surface. If there is any adjustment, it would be to set this condition, I think.
I think the sign convention *should* be +ve for a convex face. If so, the needle on Fizzy's will turn anticlockwise as the plunger goes in. (I could easily be wrong though.)
I think the sign convention *should* be +ve for a convex face. If so, the needle on Fizzy's will turn anticlockwise as the plunger goes in. (I could easily be wrong though.)
Yes anti clockwise!
Misterg
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Radius of the mug (in metres) *should be* = 0.523 / (gauge reading)
slim_boy_fat
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This place never ceases to amaze me, with the range and depth of knowledge available. 
You could use it to measure how much air you put into a balloon...It might have an engineering use. Look at 'radius of curvature' in the Wiki page:
Lens clock - Wikipedia
en.wikipedia.org
If you applied it to an ISO mugforscale, does it give a meaningful result?
Definitely!This place never ceases to amaze me, with the range and depth of knowledge available.
I guessed I would get a quick answer
I will try it on one filled with hydrogen - using a candle to see by of course
