Anyone ever use this table gauge?

[beaujolais]

Has anyone ever used this table gauge?

https://products.gemappraisers.com/pc-43-1-table-and-measurement-gauge.aspx

What do you think of it?

Say, when measuring a table, I guess one measures from the outermost table corner to the opposite outermost?

Thanks.

 

[freefly]

Date: 10/10/2009 7:50:44 AM
Author:sonomacounty
Has anyone ever used this table gauge?


https://products.gemappraisers.com/pc-43-1-table-and-measurement-gauge.aspx


What do you think of it?


Say, when measuring a table, I guess one measures from the outermost table corner to the opposite outermost?


Thanks.

I don''t know about this one, but the one at GIA was a PIA! Your hands had to be super steady or you couldn''t take a measurement. And yes, you do measure from one end of the table to another. Sorry I can''t be of more help!

 

[beaujolais]

Thanks F.F.

 

[Circe]

Freefly is totally right - the GIA one *is* a pain! It''s ridiculously flimsy, and I''m damned if I can see how it''s supposed to work if you don''t have access to a microscope ... I guess that''s when you get good at the guestimation, FAST.

The bad news is, I went to a really good jewelry supply place today to ask if they had table gauges, which they didn''t, but they said they could order one ... for $130 bucks. And when I mentioned I''d seen one for $20 on the internet, they chuckled politely and said, "Well, China." Which isn''t exactly polite (on multiple levels), but judging from past experience, they''re honest about this sort of thing. So unless I hear from somebody who uses this model regularly, I''m going to be a bit wary ....

 

[Michael_E]

I haven''t used the loupe that you''ve linked to, but do use a measuring loupe which has a single metric scale on it''s reticle. Here''s a link to the one I have as well as a number of other measuring loupes: http://www.kassoy.com/ec/1/product.asp?idDept=329&idProduct=2481

These things are really handy for measuring not only tables, but girdle thickness and lengths of facets in order to work out angles and so forth. I think that Peak optics also makes these with a built in light. You still need to be handy with tweezers though, ( I always make sure a have a cloth on the table before I mess around with tweezers and slippery stones).

 

[beaujolais]

Cool. Thanks Mike. So, I guess the measuring mechanism is controlled by turning part of the cylander?

 

[Michael_E]

No, the measuring part is just a very finely printed ruler on a glass plate at the base of the lens assembly. It's always in focus and as you bring the loupe up to an object both the ruler and object come into focus and you just measure as if you're using a ruler. After a little use you can estimate in between the ruled lines and get within about .025mm or so. This is about 1 thousandth of an inch and is much finer than a human hair. Close enough for most people.

 

[beaujolais]

Thanks again, Mike. So the ruler goes through the middle or off to the side a bit? Something like that?

 

[Michael_E]

The scale goes right through the middle. The top of the scale is a carat weight estimator and the bottom is in millimeters. Here''s a picture through the loupe at the scale.

 

[beaujolais]

Thanks again, Mike.