Comments on: Digital Scale Comparison: GemPro 500, AY123, Sartorius GD503

By: DaveS

DaveS — Wed, 12 Sep 2012 04:56:23 +0000

“Could be 20g, 50g, 100g… doesn’t matter as long as that calibration weight is certified to be that specific weight.”

This is simply wrong. All a calibration weight does is verify that the scale is accurate at that weight. It can not guarantee that a weight far from the calibrated weight is accurate. Even with two calibration weights, there is no guarantee of accuracy between those two points, but you do have significantly fewer possible sources of error than with just one point. Before a loading session, and after calibration, I always verify the accuracy using weights within about 25% of my desired charge weight.

By: Mike H

Mike H — Tue, 11 Sep 2012 16:29:34 +0000

There is another technology used for weighing precisely that I have never seen referenced on this web site called tuning-fork sensor Analytical Balance. The one I have is made by a company called Vibra and it is amazing.

Here’s a web site for you. http://www.vibra.co.jp/global/products/analytical/ht_htr/index.html

I have one of these and have found it to be incredibly stable and is impervious to magnetic interference from items like nearby cell phones or space heaters. The model I have was a bit pricey but has internal automatic calibration that initiates on startup.

I bought mine from a dealer in Montreal.

A tuning fork balance has many advantages over load cell or magnetic force reconstruction balances so have a look.

By: Greg J

Greg J — Sun, 09 Sep 2012 22:23:41 +0000

When weighing powder, I do not see the practical value of a 0.005 gr accuracy. We’re measuring powder, not plutonium.

As long as it is around 0.1 gr, of the baseline charge, I’m happy. I don’t care if that, say 30.8 gr is really 30.9 as long as it is repeatable from day to day.

I guess some folks are measuring something other than powder.

By: Jay

Jay — Tue, 11 Oct 2011 17:23:31 +0000

A calibration weight has no relationship at all to weighing operations (i.e., it makes no difference what size the calibration weight is, as long as your scale can support the weight). All a calibration weight does is allow your scale to be “calibrated” against a known, “guaranteed” weight. Could be 20g, 50g, 100g… doesn’t matter as long as that calibration weight is certified to be that specific weight. Using a 100g certified weight or a 1g certified weight is not going to make any difference in the subsequent weighing outcomes, whether light powder loads or otherwise, assuming the calibration weights are certified.

>>>>>
Have often wondered why calibration to a weight of 100 grams makes any sense when charge weights are usually less than 100 grains (even for African game calibers.

I would think that calibration weights should either fall within the range of charge weights (presumably at the middle) or at the top end of the range.

By: steve

steve — Mon, 10 Oct 2011 23:50:21 +0000

100 g = 1543.233 gr
gram to grain conversion

By: steve

steve — Mon, 10 Oct 2011 23:44:29 +0000

This is great info on digital scales.
What about the average Joe, you know the guys that bought a RCBS digital scale and powder dispenser combo, or the other brand equivalent?
How accurate are they in comparison to the lab equipment?

By: Dave White

Dave White — Mon, 10 Oct 2011 23:37:32 +0000

Have often wondered why calibration to a weight of 100 grams makes any sense when charge weights are usually less than 100 grains (even for African game calibers.

I would think that calibration weights should either fall within the range of charge weights (presumably at the middle) or at the top end of the range.

By: Matt Pitchon

Matt Pitchon — Mon, 10 Oct 2011 20:57:39 +0000

I have a AY123, and could not duplicate the above results. My scale is extremely accurate. Environmental conditions are important with this scale. The room I use has a constant temperature and humidity. My steel bench is bolted to the wall, and rests on a concrete floor. I leave my scale plugged in but not on.

In over 30 measurements of 141gr, 28 were exactly 141, and 2 were 141.02. After three days, I had no drift, and performed the test again, with the same results.

Note that the video shows the 123 jumping as powder is added. The reason is the scale is in the default setting, which is for single weightings. When changed to ‘Filling’ mode, the scale reacts very quickly, and in my case accurately. Trickling is easy in the ‘Filling’ mode.

My experience is the AY123 is an excellent scale, but is sensitive to environmental factors. The GD503 is way better and is also way more expensive.