Craig Clark on fri 9 dec 05
I've read a few of the posts on this thread and, as a long time triple
beam balance user (Ohaus), the thought of what happens over the long
haul with the accuracy of the scale popped up. Does anyone know whether
or not a digital scale needs to re-calibrated every so often, and if so,
what the cost is or where one would get it done?
Just a question
Craig Dunn Clark
619 East 11 1/2 st
Houston, Texas 77008
(713)861-2083
mudman@hal-pc.org
WHere we are emerging from the devil incarnate icy winds from the great
white north......And no, I'm not a candy ass! It was 85 degrees around
here last Saturday and literally below freezing last night....
steve graber wrote:
>this discussion went on a rec.crafts.pottery postings years back. i have a triple beam scale, and don't use it because i don't like fussing with it & my glasses aren't too good.
>
> digital is easy enough to use that you WILL use it.
>
> some talk went on that people might buy digital scales from police stations as confiscated material from drug raids. some police stations do sell this equipment, some don't. the policy of those who don't is that they don't want the equipment falling back into the trade they got it from.
>
> still, there are places to get digital equipment for cheaper then full price. many companies use digital scales to measure out parts in inventory. there may be a company around you that have old scales to buy used. ~ or e-bay...
>
> see ya
>
> steve
>
>d milton wrote:
> I am looking for some feedback on a triple beam scale vs. a digital scale
>for weighing both 300 gram test batches and 3000 gram buckets. Is one a
>better choice than the other? What do you typically look for when selecting
>a good triple beam or digital scale? I am in the market for a scale for my
>glaze pantry and am curious as to what others think. Any thoughts would be
>much appreciated! Thanks so much!
>
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Steve Slatin on fri 9 dec 05
Craig -- I can't speak for all digital scales, but some don't have any
special means to re-calibrate. OTOH, most have a zeroing function
that's automatic on setup that provides a partial recalibration.
I have a few known weights and I use tareing to get other numbers
and use that to check my scale every few months. So far so good.
(If you lack any known weights --- Take a volume
measure that's heavy and one that's light, like a glass and a
plastic 2-cup measuring cup; weight each and note, add 1 cup
water to one, weigh, pour water to other cup and weigh; subtract the
tare weights of the cups and if the numbers are not close to identical
you're no longer weighing accurately. A pint's a pound, two cups
to a pint, so 1/2 pound, 454 grams to a pound, 227's the target.)
The problem of accuracy at extremely low weights remains serious
for less-expensive electronic (strain gauge) scales like mine. For
the few things that demand accuracy at very low levels (weighing
cobalt or maybe copper) for test batches and such I weigh a 5 or 10
gram batch out, and do physical division to get the fine amounts.
Getting down to 1 g with reasonable accuracy isn't too hard, and
I don't need a more expensive, harder to use, scale. A good lab
scale (the kind in a box to seal out air movement during weighing)
would be best, but is an extraordinary expense.
If you want to avoid the estimating inherent in my method, getting
two electronic scales; one a 'jewelers 0.1 g accuracy' scale and
one a 2000 g maximum scale would be possible on e-bay or from
"Old Will Knott" or a similar on-line vendor for no more than $70
and you'd have extraordinary accuracy at both small and
intermediate-weight levels.
Very much just my 2 cents -- Steve Slatin
Craig Clark wrote:
I've read a few of the posts on this thread and, as a long time triple
beam balance user (Ohaus), the thought of what happens over the long
haul with the accuracy of the scale popped up. Does anyone know whether
or not a digital scale needs to re-calibrated every so often, and if so,
what the cost is or where one would get it done?
Just a question
Craig Dunn Clark
619 East 11 1/2 st
Houston, Texas 77008
(713)861-2083
mudman@hal-pc.org
WHere we are emerging from the devil incarnate icy winds from the great
white north......And no, I'm not a candy ass! It was 85 degrees around
here last Saturday and literally below freezing last night....
steve graber wrote:
>this discussion went on a rec.crafts.pottery postings years back. i have a triple beam scale, and don't use it because i don't like fussing with it & my glasses aren't too good.
>
> digital is easy enough to use that you WILL use it.
>
> some talk went on that people might buy digital scales from police stations as confiscated material from drug raids. some police stations do sell this equipment, some don't. the policy of those who don't is that they don't want the equipment falling back into the trade they got it from.
>
> still, there are places to get digital equipment for cheaper then full price. many companies use digital scales to measure out parts in inventory. there may be a company around you that have old scales to buy used. ~ or e-bay...
>
> see ya
>
> steve
>
>d milton wrote:
> I am looking for some feedback on a triple beam scale vs. a digital scale
>for weighing both 300 gram test batches and 3000 gram buckets. Is one a
>better choice than the other? What do you typically look for when selecting
>a good triple beam or digital scale? I am in the market for a scale for my
>glaze pantry and am curious as to what others think. Any thoughts would be
>much appreciated! Thanks so much!
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
>
>
>
>
>---------------------------------
>Yahoo! Shopping
> Find Great Deals on Holiday Gifts at Yahoo! Shopping
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
>
>
>
______________________________________________________________________________
Send postings to clayart@lsv.ceramics.org
You may look at the archives for the list or change your subscription
settings from http://www.ceramics.org/clayart/
Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
Steve Slatin --
And I've seen it all, I've seen it all
Through the yellow windows of the evening train...
---------------------------------
Yahoo! Shopping
Find Great Deals on Holiday Gifts at Yahoo! Shopping
Michael Wendt on fri 9 dec 05
We use Ohaus model d-50s and d-100. Both drift with time and require
periodic adjustment.
Since we use them in a trade legal setting, they are checked once a year and
the Bureau of Weights and Measures suggested I make a set of calibration
weights to check accuracy between recertification visits.
I went to the local gun shop and bought a 15lb bag of #6lead shot and filled
various containers to the specific values using the Ohaus triple beam
balance and found that even if the scale should drift, the calibration
weights can be used.
Most curious, even if the scale has drifted, the drift is linear so for
glaze and clay body formulations, as long as the same scale is used, the
results are still valid;-)
Regards,
Michael Wendt
Wendt Pottery
2729 Clearwater Ave
Lewiston, Idaho 83501
USA
wendtpot@lewiston.com
www.wendtpottery.com
Craig wrote:
I've read a few of the posts on this thread and, as a long time triple
beam balance user (Ohaus), the thought of what happens over the long
haul with the accuracy of the scale popped up. Does anyone know whether
or not a digital scale needs to re-calibrated every so often, and if so,
what the cost is or where one would get it done?
Just a question
Craig Dunn Clark
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