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A dependable digital jeweler's scale


#1

Folks,

I’m in need of a jeweler’s scale, but am reluctant to buy just
anything without getting some advice on this. Is there a scale for
modes: grams, ounces, troy ounces, pennyweights and pounds or
similar that doesn’t cost an arm and a leg. I saw one in the Rio
catalog called Ohaus Ruby 300 scale that is in the right price range
for me, but hesitate to buy it not knowing how reliable or the
quality that it might be. It has a calibration weight too so it
"appears" to be what I could use. I’d just feel better if I got some
experienced jewelers that could comment on this.

Any other on what to look for in a scale would also be
helpful.

Thanks in advance,
Mary


#2
I'm in need of a jeweler's scale, but am reluctant to buy just
anything without getting some advice on this. Is there a scale for
modes: grams, ounces, troy ounces, pennyweights and pounds or
similar that doesn't cost an arm and a leg. I saw one in the Rio
catalog called Ohaus 

O’House makes good scales. I don’t know that particular model, but
they are well known, and produce quality scales.

Some things to look out for, that can trip you up.

If you need a scale that’s “legal for trade”, then be sure it’s
actually stated as such.

Also, just because it’s modes may include the units you wish,
doesn’t mean it will do what you need. Pay attention to the maximums
it can weigh for a given unit, as well as the resolution. For
example, you can buy nice looking multimode scales that include
carats in the units. Some of these only weight to within a half
carat, while others, usually those having a lower maximum load, might
weigh to withing.05 carats (five points) If you’re weighing lots of
semiprecious stones or rough, perhaps that’s enough. But for more
costly goods, you need higher resolution, to .01 carats at least.
And even those may not be accurate enough, since that last decimal
place on many such scales isn’t totally accurate. For that, you’d
need a scale that goes one decimal place further, such as.005 carats.
If such a scale says it weighs to within a half point, then you can
put reasonable trust in the “points” decimal place, even if the.005
might be wobbling between.005, and the next increment up. Even better
(found on proper diamond scales, would be a resolution of .002 or
better. Anyway, you get my point. Look not for just the units you
want, but the maximum loads it can weigh and the resolution. Don’t
expect a scale that can weigh up to ten pounds, to also be able to
weigh down to a milligram or two. The other thing to point out is
that some units, while useful, might be reduntant. If your scale
reads in pennyweight, does it actually also need to read in troy
ounces? That’s an easy conversion. Same with grams to carats, if the
grams resolution is good enough to translate into the resolution you
need in carats. (for example, a laboratory grade scientific scale
might be only metric grams and milligrams. But if such a scale
measures down to a tenth of a milligram, then you’ve got yourself
one hell of an accurate diamond scale too. This can be of help if,
for example, you’re looking at scale on ebay. You might find such a
used scientific scale for a lower price than a less accurate new
diamond scale…

Hope that helps.
Peter Rowe


#3

All my scales for the past 10 years have been Ohaus, AAA in my
books.


#4

Hi Mary,

I have a couple of Ohaus scales, not that one, but a mechanical one
and a 30Kg electronic one, and I would heartily recommend them. I had
a customer buy a cheap one off E-Bay and it was noticeably
inaccurate. If you are going to use it for trading, ie in a shop to
buy scrap I believe you have to get one that is officially calibrated
which costs a lot more, but for your own use Ohaus are good.

regards,
Tim Blades


#5

Mary,

Call Stuller Tools Tech Line 800-877-7777 ext 4300 and ask about EK
Series 600i (51-4071) or 1200i (51-4072) models. These scales are
NTEP Approved and should fit in the budget…

Chris


#6

How often should a scale be calibrated that is not being used in
trade?

Mitch Adams