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Accuracy of new coin scale

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I just acquired a new coin scale that supposedly has an accuracy of 0.01g. It didn't come with a calibration weight so I have none, however, the scale will zero itself out on turning on. Not sure if this means much.

 

I placed a 1986 Silver American Eagle on the scale. It's documented to have a weight of 31.101g. My scale measured it at 31.16g (a difference of about +0.19%). I tried weighing it with a flip and without the flip...same exact weight.

 

Here's my question, is it about as accurate as I will get from most scales of 0.01g accuracy or do I need to return it?

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There is a tolerance for stuff produced by the mint, but I don't know off hand what it is, or if it's tighter for bullion than circulation stuff, but a quick search should find it. The fact that you get the same weights with and without the flip is disquieting, though. My next step would be to weigh the flip by itself. If you have 10 flips, weigh them all together so you can determine the usable precision of the scale.

 

You can (should) also check accuracy with current, uncirculated coinage and compare against this table:

 

Coin specs

 

I can't remember if over-the-counter medications include the weight per tablet of inactive ingredients as well as active ingredients, but you might be able to use these as calibration weights as well.

 

What is the brand of the scale?

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To clarify...with and without the flip, the COIN weighed the exact same (after subtracting the flip weight).

 

Scale brand is AWS. It was a cheapie but seemed to have great reviews.

 

More weighings:

 

1987 (1)=31.40g

1987 (2 - diff coin)=31.44g

1987 (3 - diff coin)=31.25g

1991=31.19g

 

 

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Twenty new nickels should weigh 100.00 grams if they are clean and free of dust and fingerprints. Take the same measurement 10 times, then average the results.

I use a piece of lab filter paper on the scale, null that, then add the coin. That is repeated ten times for any one coin.

 

A breath of air will change your readings.

 

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Some more tests:

 

2 newer BU Lincoln cents - 2.47g and 2.48g (documented weight=2.5g)

3 BU state quarters - 5.69g, 5.71g, and 5.76g (documented weight=5.67g)

 

I weighed each one at least 2-3 times and the weight came up the same each time for each.

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You keep saying documented weight. A documented weight is a weight that has been weighed on a calibrated and certified scale. I think what you mean is either official or defined weight. For example the one troy oz of silver is DEFINED as 31.101 grams. The silver eagle is guaranteed to contain one try oz and to make sure it does they actually make them slightly heavy. (And unless you weigh and adjust each planchet individually every piece will vary slightly from every other.)

 

In the case of the Zincoln cents the official or legal weight is 2.5 grams but the mint has a .1 gram allowed tolerance range, so they can weigh anywhere between 2.4 and 2.6 grams and still be considered of legal weight.

 

The coppernickel clad quarters have an official weight of 5.67 grams, but the legal tolerance on these coins is +/- .227 grams So they would be of legal weight if they weigh anywhere fro 5.897 grams to 5.443 grams.

 

So all of the coins you have weighed are within their proper weight ranges.

 

RWB said that 20 unc nickels would weigh 100 grams. Well a random selection weighed all together should weigh very close to that, but could still be off a little. The tolerance on that 5 gram per coin weight is +/- .19 grams (which is a huge variability). In theory some of those 20 will be heavy and some will be light and on AVERAGE 20 pieces will weigh 100 grams. But since you can't guaranteed that the heavy ones will exactly cancel out the light ones they will probably still be slightly off of that 100 gram figure. But in reality 20 coins could weigh as little as 96.2 grams or as much as 103.8 grams.

 

When you are discussing scales and talk about a calibration weight, that weight isn't just a random weight of a set amount. A true calibration weight is a weight that truly is documented and has been weighed on a calibrated and certified scale and then adjusted to weigh PRECISELY the amount that is marked on the weight. So a 50 gram weight, and 50 gram calibration weight are NOT the same thing. (calibration weights should never be touched by hand since dirt and oils left on the weight by your hands throws off its calibration. You pick it up and it no longer weighs EXACTLY 50 grams.)

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Conder101 is correct - minor coins are not individually weighed, as were gold and some silver. A roll of new nickels could easily include pieces over- and under-weight -- possibly the entire roll.

 

As an aside: gold coins were individually weighed and all had to be within the tolerance. However, when bagged, the total bag tolerance was much less, so the adjusters and baggers had to mix "good light" and "good heavy" pieces so the entire $5,000 was within the bag tolerance.

 

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I just acquired a new coin scale that supposedly has an accuracy of 0.01g. It didn't come with a calibration weight so I have none, however, the scale will zero itself out on turning on. Not sure if this means much.

 

I placed a 1986 Silver American Eagle on the scale. It's documented to have a weight of 31.101g. My scale measured it at 31.16g (a difference of about +0.19%). I tried weighing it with a flip and without the flip...same exact weight.

 

Here's my question, is it about as accurate as I will get from most scales of 0.01g accuracy or do I need to return it?

What is the altitude and relative humidity of your location?

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Gravitational attraction and atmospheric pressure effect on a coin (as opposed to a human/animal/etc.)would be extremely minor and most digital scales are self correcting, by internal programming, or a zero out adjustment ability.

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Sounds like your scale is pretty good. I've used a cheapo digital scale with 0.01g resolution for years and it's good enough for 99.9% of my needs.

 

Comparing the nominal weight of a few common coins to your scale's read-out should confirm that it is adequate for your needs.

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I just acquired a new coin scale that supposedly has an accuracy of 0.01g. It didn't come with a calibration weight so I have none, however, the scale will zero itself out on turning on. Not sure if this means much.

 

I placed a 1986 Silver American Eagle on the scale. It's documented to have a weight of 31.101g. My scale measured it at 31.16g (a difference of about +0.19%). I tried weighing it with a flip and without the flip...same exact weight.

 

Here's my question, is it about as accurate as I will get from most scales of 0.01g accuracy or do I need to return it?

What is the altitude and relative humidity of your location?

I'm at about 5800 feet with humidity usually under 20%.

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take 20 different coins/items and weigh them and record the weight

 

do this every day for a week

 

 

are they the same or within 0.01g?

 

 

what makes you feel the scale is inaccurate? the numbers you get are different than what is in the redbook?

 

why do you need to know weight of anything to within 0.01g?

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What I should have said was:

 

A $5,000 bag of 250 double eagles must have weighed 129,000 grains with a tolerance of 4.8 grains. So you should take one of the sealed bags of double eagles from under the mattress, and put the coins on your scale. Their total weight should be between 129,004.8 grains and 128,995.2 grains. Be sure to weigh any flakes of gold left in the bag, too.

 

:)

 

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Hello dude.In my point of view flip is not consider the weight is increased or decreased when you weight the coin on the scale same both sided weight or single side weight do you consider.Some error is occurred when you weight the coin on the scale its not a big problem.

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