Digital Scale calibration

[jtk5768]

I am wondering if the calibration weight on my digital scale is oxidized (brass weight) does this have an impact on my calibration? Is oxidized metal lighter, heavier or same?

[Seismic Sam]

Heavier. Seeing as brass can't evaporate at room temperature, the oxide/corrosion products mean there are extra oxygen molecules or perhaps chloride molecules from the sweat on your fingers that have bonded/reacted to the brass.

That being said, if your scale has a precision of .01 gram or 0.1 grain then it's probably a cheap POS and the check weight is a non-issue. If it's a .002 gram or better jeweler's scale, I'm not sure that you're in trouble anyway. If it's a 100 grain check weight, probably not a problem. Your .338 Lapua won't be able to tell the difference. If it's a 100 gram check weight don't worry about it at all. If it will make you feel better (and that's probably all it will do), buy a new weight.

[45Badger]

I'm a beam scale guy. Has worked for mr for the last 15 years. Never one to leave well enough alone, I am thinking digital for Christmas. Any pin ions on quality digital scales? Do any need calibration more/less than others? What size check weights should I use on a digital?

Sorry if this is a hijack.....

[Erud]

You really need to spend a fair amount of money to get one that's worth anything. At the lower end, they will be much less accurate than a beam scale. At the low/mid grade, there are models that are accurate, but not really made for powder and don't handle trickling well, drift a lot, and require frequent re-zeroing. If you really want something accurate, you should basically disregard anything that is branded by any of the reloading press companies right out of the gate. If it says Dillon, Hornady, RCBS, etc, don't buy it. Not that they don't sell serviceable products, but "accuracy" is not what you will get from them. Once you start spending some money, they get better, but you need to know what you're looking at and I'd recommend doing some serious research before you make a decision. The very least I'd recommend would be the GemPro 250, which is pretty popular among reloaders, but also has a pretty spotty record for reliability. Search around and you can find a ton of folks talking about sending them in for repairs and complaints of excessive drift. I've had a few different digital scales and I've learned that the cheap ones are more trouble than they are worth to me. The one I have now is accurate to .005, and stays rock-solid on zero. Fluorescent lights have no effect on it, and it can read trickling powder as fast as I can trickle it. It was not cheap though. A phone call to the folks at balances.com would get you a lot of useful info on this topic, they are very knowledgeable.

I expect Seismic Sam will be back shortly to tell me(or you) that I don't know what I'm talking about...

[Seismic Sam]

Actually, Erud, you nailed it perfectly. And you did it in a more concise way than I could. Buying a digital scale that works is a lot tougher than you think, and your chances of getting a good one without doing a lot of research are practically nil.

[PhilaBOR]

So do you have the GemPro or a different one? I didn't see the brand/model of the one you like.

[20mm]

Most digital scales self-calibrate when you turn them on. Read the damn manual.

[Erud]

PhilaBOR,
I have a Sartorious GD503. It is rock solid in every way, though I have to admit that it is major overkill for most reloaders. I take this stuff pretty seriously, so I find myself getting deeper into the weeds than most would like to be.



20mm,
As usual, you are out of your element. Try to stay quiet while the adults talk.

[Seismic Sam]

FYI - the GD503 is now obsolete and has been replaced by

http://balance.balances.com/scales/569

Both scales are 4 place (meaning .0001 gram accuracy, or .0015 grain accuracy) and are a bit more than a G-note. Seeing as I'm Wildcatting these days, I laboriously weigh all my powder with a Mettler .001 gram accuracy scale, and I will admit there are times where I could use that extra decimal point in doing 0.1 grain increments for chrono work.

[20mm]

20mm,
As usual, you are out of your element. Try to stay quiet while the adults talk.

20mm doesn't have an element, it's a radius followed by penetration, and it's never quiet.

Don't worry, I know you're just upset you didn't get a prometheus dispenser.

[Erud]

20mm,
As usual, you are out of your element. Try to stay quiet while the adults talk.

20mm doesn't have an element, it's a radius followed by penetration, and it's never quiet.

Don't worry, I know you're just upset you didn't get a prometheus dispenser.

Not really, I actually have one of those as well. The GD503 gets used for load development, and the Prometheus is for when development is complete and it's time to load in volume.



In light of your clever reply, I'll revise my earlier comment to:

"As usual, you have nothing of value to add to the topic."

Still waiting for you to post up some of your shootin' credentials from that other topic....

[OldmanFCSA]

Erud,
The Denver Instruments MX-123 scale I received from you works great, but the company was bought out and their product is no longer supported.

[Erud]

Erud,
The Denver Instruments MX-123 scale I received from you works great, but the company was bought out and their product is no longer supported.

Glad to hear it - the working great part I mean. After I sold that one to you I kind of went away from the high-accuracy digital's for a while. That didn't last for too long though, and my shooting pursuits pulled me even further into the weeds. It is nice to know with absolute certainty that 47.2 grains of Varget weighs 47.2 grains every time...