I have never owned a scale but would like to get one. Any help on what to get would be most appreciated. I don't know why I never got one but the time has come. How heavily do all of you rely on them?
Buy one that claims accuracy to .01 g. and don't count on it beyond the .1g level. I have owned two from eBay at $10 each. One was consistent and matched up pretty well with professional dealers' scales. The other was pretty much junk beyond the .1g level. Of course, for $10, perhaps .1g is enough.
I agree that you should buy a scale that specifies accuracy to .01 gram. I personally use a more expensive scale that is also useful for measuing gun powder & reloading bullets. My scale is called the Dillion d-terminator. Here is a link: http://www.dillonprecision.com/content/p/9/pid/25213/catid/7/D_Terminator_Electronic_Scale
Here's a .01g scale that has worked well for me. https://www.wizardcoinsupply.com/professional-digital-table-top-scale-500-x-.01-g.html
My biggest problem with these scales is the matter of calibration. My two old scales came with calibration weights but these weights did not weigh the same to .01g which is supposedly the accuracy of the scales. I see some now advertised that come with both a heavy calibration weight and a light 'test' weight that you are supposed to use after calibrating. If you calibrate a scale based on 100g and test with a 10g weight, I suppose you could fudge the calibration to make the 10g weight exactly 10g but there is still no way of knowing how close to 10g that 10g weight really was. I saw some appeal in a model that came with two 100g weights. The first obvious step would be to weight both of them and know that you were in trouble if one weighed .5g more than the other.
i've got a 10 buck cheapie scale with a .1g resolution. it seems to be accurate, i've tested several times with pocket change and it always come out ok and be consistent. if this one dies or acts up, i'll get a nicer one that goes to 0.01g. if you're going to weight some little greek obol fractional unit thing, being off by even 0.1g would relatively large error. that one medjoy posted looks pretty nice.
Find 10 new looking nickels which are supposed to weigh 5.00g. I just did and found a range of 4.97 to 5.10g (using my scales as currently calibrated) with no more than three of the coins within .01 of each other. Calibrating a scale using nickels might not be the best move. On the other hand a random group of twenty nickels may well weigh as close to 100g as the low price calibration weights sold on eBay. I simply do not know how to tell which of the claimants to 5.0 really is that weight. I have considered buying a .001g scale to weigh the calibration nickels but I'm not convinced that their being marked to three digits means that their accuracy is better than the .01 models.
This thread made me want to try again so I also ordered an upgrade to my current scale and will report on the outcome.
Actually, Doug your scales might be exactly correct, as the nickels have a specified weight of 5 grams +/- 0.13grams, so for gov. specs, any nickel from 4.87 to 5.13 grams may have come from the mint like that. Because the last digit of a digital scale reading is a rounded result, so best is to get a scale that reads 1 more digit than you will need. It will still be rounded, but you can ignore it as accurate. US coins generally have tolerances with two decimal digits, so one with .001 readout should suffice if you are seeking to identify off-metal coins, counterfeit, etc. A calibration weight is important to use to correct the electronic sensor in the scale occasionally, especially if you drop it. You can make one with a stack of nickles if you weigh them on another scale that has been recently calibrated. I would think that for ancients , the tolerances might be higher, but I wouldn't know who might have original weights Modern coins often give a nominal weight without the tolerances, so everyone thinks they have an error. Jim
Yesterday I received my newly purchased scale. I suppose it would be inappropriate to give the link or name but I will do a short review of features and you can decide if you think I was correct in my choice. First, I was not willing to pay the price for what might have been the 'best' scales and that may mean that the one I have will not last. I can not tell in a day or a year if it was good in that respect. My previous junk scale had a calculator built in to the cover but the display on that calculator never worked. Guarantees mean nothing when you have to pay the return postage which is half of the price. The new scale measures up to 300g which is way more than my heaviest coin and claims accuracy of .01g. It was $16.99 postpaid which is more than several but I paid the extra for one specific feature. It came with two 100g calibration weights and one 10g weight to check the results. Calibration requires both of the 100g weights. Some scales came with a single 200g weight or some other configuration but the pair of 100g weights allowed me to weight each separately and compare. Both of the weights had a machined dimple in the bottom where they had been reduced to the weight from the original casting AND both had rough gouges in the base as if someone had used a knife to remove just a bit more metal. I suspect this explains how both weights were exactly the same weight to .01g on my old scale and the new one and read 100.00g on the new one suggesting it was calibrated recently. The 10.00g weight also read exactly 10.00g. I then used one of those 100g weights to calibrate my old scales which now reads also exactly 10.00g. As I see this, the value received in the set is more for the matching 100g weights than it is for the scales which strikes me as perfectly fine for my uses (as was my old scale except that I had no way of calibrating it unless I used the guesstimate by nickels method. I weighed my assemblage of new looking nickels and found a range of 4.94 to 5.07g. Randomly selecting five, I got 24.99g so that really is not all that bad unless you randomly selected the wrong nickels and either added a .05g error with each one. My next step will be to weigh all my recent purchases on both scales and to compare those numbers with the results provided by the sellers. Obviously I expect a company like CNG to own a better scale than some eBay amateur seller but it will be interesting to see if I can predict what a coin will weigh on my scales from what a seller said it weighed and how the last several coins I got from them weighed. The 10g check weight is way too heavy for most of my uses. I would like to have a really accurate .05 weight just to see if things are linear. Does all this matter? Not really but it was fun. I do believe that either of my cheap scales is capable of weighing accurately but I also believe that you need the calibration weight to feel comfortable with that last digit. Most of us could do well with a .1g scale but I see no reason not to but the .01g model unless you plan on weighing really heavy objects (I collect meteorites, too but most are under 300g so this will be fine). I do notice that there are a few scales claiming .001g accuracy but having a range only up to 20g and many of my coins are over that. All the ads and paperwork warn that damage to the scale will occur if you weigh something heavier than the stated limit. I won't be testing that feature.
