Measuring pearls

[Mervione]

I´ve a question about measuring pearls. How on earth are people that deal with pearls able to measure 0,1 mm differences? I´ve been wondering about this for a while.

[Ashley]

Digital Caliper

[Ashley]

This allows you to get very, very accurate!

[Mervione]

Wow! I have to get one, are they expensive?

[Hanaleimom]

I got one at a local hardware store for $9 on sale. There are other more expensive models that this store sells. I don't know the difference as far as how much more accurate or whether there are more features. But the inexpensive one is good enough for me.

[Ashley]

Mine is pretty run of the mill as well, goes through batteries pretty quickly unless you remember to switch it off after every use. Speaking of... mine is blinking at me like crazy every time I turn it on- think I'm due!

[Cathybear]

Mine turns itself off automatically after a little while (maybe a minute of no use), it's plastic (won't scratch pearls) and was about 20 dollars. The stainless steel one was a lot more. I've had mine about 6 months or so and I've just replaced the battery for the first time.

[jerin]

Wow! I have to get one, are they expensive?

CLAS OHLSON, SEK 398:- = digitalt skjutmått., art nr 31-956
For durability as well as balance I recommend this metal caliper instead of the plastic one, even if it is much cheaper (SEK 198:-), art nr 31-3155.
You can order one online, www.clasohlson.se.

[J Marcus]

Having used digital, dial and Vernier (manual) caliphers I have to vote for the manual/vernier ones. They are just as accurate as digital or dial, don't need batteries and are, IMHO, far more durable. It doesn't seem to take much of a shock to wreck a digital or dial one and good luck trying to re-calibrate it if you can even get it working again. The manual ones aren't impervious to damage but, if not completely ruined, one can usually restore and recalibrate one. One way to prevent most scratching with a steel calipher is to take very fine (600 grit or more) and gently round and smooth off the sharp edges of the jaws--not the end points, though. Avoid sanding or polishing the flat measuring surfaces of the jaws as this will change the distance between them. If one is very carefull and has the right equipment one can even polish these rounded corners with tripoli or Fabuluster. I believe that Grizzly Imports sells a good one for under $20.00. I'll try to find a link.

http://grizzly.com/products/6-pc-Mea...Tool-Set/G9790

The only manual one that I could find online with Grizzly is as part of this set of measuring tools. It's a good deal, I think if one needs all that. Their headquarters & main showroom are here in Bellingham and I've purchased two of these caliphers there. Next time I get up there I'll try to remember to see if they still have them. I would suggest calling or emailing them and asking.

Just found vernier caliphers listed for $10.22 USD at:

http://mcmaster.com

They are item # 2192A21 or enter "vernier calipers" in the search function and scroll through. I'm not familiar with the company or product, though.

-------------------------
Marc
http://www.flyrodjewelry.com/home.html

[gravityalwayswins]

Being an engineer, and having spent years working in a machine shop using calipers to test high-precision parts used for medical devices, I'm SOO excited to see calipers here on PG - my profession and my passion are colliding! It's so cool!

Marc - I'll back you up on the manual calipers. I like them better, too, even though it takes a wee bit of time to learn how to read them. As for the McMaster-Carr link, I can't speak directly to their calipers but I ordered from them a lot for shop supplies and mfg tools in the past and was always satisfied, but the most recent time was 5 years ago or so.