Scales - what’s a good coin scale 1 1

[kellyt]

I went and got another digital scale. The kitchen flat kind. It reads only whole numbers for grams. What’s a good one that will read 11.3 and not just 11. Or 12.8 and not just 13? 

[Mr.Bill347]

Its better have a fractional measure. I have a food scale as well, and it doesn't do fractional grams and that has been limiting at times. Hers one on Amazon for fifteen bucks.

[JKK]

I have one of these and am satisfied with it.

[James Zyskowski]

Here’s one  from eBay. Anything similar. I can’t see JKK ‘s but he’s very smart so I listen to him. This is food for thought 

 

Welcome 🙏!!

Edited September 10, 2021 by James Zyskowski

[Greenstang]

Whatever scale you get, make sure it reads to at least two decimal points.

One decimal point is not good enough for coins.

[RWB]

If you can afford it, buy a digital scale with a 100g capacity and gram measurements to 3 decimal places. You will then round the display value to two places for reporting final results. Make sure the scale can be easily calibrated and that it has a tare (or net item weight) setting. Lastly, do not put a coin directly on the scale -- cut a small piece of good paper, put that on the scale, tare the weight, then add the coin.

You should do this 10 times for EACH coin, then average the 3-decimal place results and round to two decimal places in grams. If you are using Troy grains, go to 3 decimal places after rounding - this will normalize to the way the US Mint measured grain weights in the 19th and early 20th centuries.

[RWB]

Just to clarify the display decimal places --- the final display digit to right of the decimal is always an interpolation, that is, it is not repeatably accurate. Rounding accounts for the interpolation and produces a repeatably accurate result.

U.S. Mint assays and weights were supposed to be measured to the 3rd decimal place (thousandths) with a 4th place equal to either 0 or 5 - essentially an interpolation. In fact it was not until the mid-1890s that mint assays were occasionally repeatably accurate to 3 places, and well into the 19-teens until that was "normal." Alloy inaccuracy is one of the Mint's long-term "little secrets" - but there was nothing better under operating conditions of the time.

[kellyt]

On 9/10/2021 at 4:27 PM, RWB said:

If you can afford it, buy a digital scale with a 100g capacity and gram measurements to 3 decimal places. You will then round the display value to two places for reporting final results. Make sure the scale can be easily calibrated and that it has a tare (or net item weight) setting. Lastly, do not put a coin directly on the scale -- cut a small piece of good paper, put that on the scale, tare the weight, then add the coin.

You should do this 10 times for EACH coin, then average the 3-decimal place results and round to two decimal places in grams. If you are using Troy grains, go to 3 decimal places after rounding - this will normalize to the way the US Mint measured grain weights in the 19th and early 20th centuries.

Thanks! And thanks everyone!

[bsshog40]

I bought the same one that james is showing a few years ago.  Cheap price and and self calibrates. I also have calibratiin weights and it stays accurate. 

[Mr.Bill347]

On 9/10/2021 at 5:27 PM, RWB said:

If you can afford it, buy a digital scale with a 100g capacity and gram measurements to 3 decimal places. You will then round the display value to two places for reporting final results. Make sure the scale can be easily calibrated and that it has a tare (or net item weight) setting. Lastly, do not put a coin directly on the scale -- cut a small piece of good paper, put that on the scale, tare the weight, then add the coin.

You should do this 10 times for EACH coin, then average the 3-decimal place results and round to two decimal places in grams. If you are using Troy grains, go to 3 decimal places after rounding - this will normalize to the way the US Mint measured grain weights in the 19th and early 20th centuries.

RWB what is the reason you stated do not put the coin directly on the scale. ?

[James Zyskowski]

I put something on the scale because I am a clutz. You name it I can drop it. First 70 slabbed coin I bought a few years back. I opened the package and promptly dropped it on the kitchen floor. I broke it

I use cotton cloth cut in 2x2’s so I don’t scratch ding or anything. Paper works well. I just had lots of tee-shirts. 

[RWB]

On 9/10/2021 at 9:58 PM, Mr.Bill347 said:

RWB what is the reason you stated do not put the coin directly on the scale. ?

Measurements are taken to the 3rd decimal place (interpolated) of a gram....about the weight of a dust mote or two. That's why 10 measurements - to even out the errors of each measurement.

Metal-to-metal contact can distort measurements when small pieces rub off. It also lessens contamination if other measurements, such as density, are taken. In a small lab setting, filter paper discs would be used with a new disc for each measurement and light sable brushing of the coin edge. But, given that most collector handle coins by their edge, and routinely smear finger oil/dirt on the edge, such precautions are probably excessive. I use a hard, thin plastic disc and check under magnification for any particles on the coin.

Edited September 11, 2021 by RWB

[RWB]

RE: "I use cotton cloth cut in 2x2’s so I don’t scratch ding or anything. Paper works well. I just had lots of tee-shirts."

Preferably, use something that does not shed fibers - a piece of 100% polyester (no dye or UV brightener) can work well.

[Numismatic, A.A.S.]

In go bag

[J P M]

I have a plastic tray with a paper insert to keep the scratches off the tray and scale. Scratches will hold dirt after a while .

[Numismatic, A.A.S.]

On 9/12/2021 at 8:41 PM, J P Mashoke said:

I have a plastic tray with a paper insert to keep the scratches off the tray and scale. Scratches will hold dirt after a while .

You just reminded me.....I totally forgot....I better look at our larger one too. Thanks man.