Sciencemadness Discussion Board

Store Bought Scales

thebean - 18-2-2014 at 16:14

Does anyone know of any stores that sell scales down to .01g? I looked around on this sub forum and couldn't really find anything.

thesmug - 18-2-2014 at 16:22

I think that some chef/food service supply stores sell scales at a res. of 0.01 but I'm unsure of how accurate they are. They also seem to be very unreasonably priced. I believe Whole Foods sells such scales but you'll have to check your local store.

[Edited on 2/19/14 by thesmug]

Zyklon-A - 18-2-2014 at 16:28

At Walmart I saw some scales for weighing food, some of which say they can weigh 0.1g, but I doubt that they are really that accurate.

mr.crow - 18-2-2014 at 18:50

Try your local hemp store

Nickdul - 20-2-2014 at 14:54

Look for scales that are used in jewelry or for loading firearms. These are generally small and come with calibration weights. Testing my 10g/0.001g scale against standardized weights shows deviation of +/- 3 mg along the entire range, which is not bad for a <$20 Chinese scale. I also have a 500g/0.01g model, but I haven't done any testing. Watch out for contamination, as these scales are not meant for continuous lab work and if exposed to chemicals (powders and deliquescent chemicals getting inside) will malfunction. I had one measure inaccurately, so I opened it and cleaned it out with pet. ether and a no-lint cloth, and it worked perfectly. Another was dropped from a considerable height and the casing was severely damaged. Opening, reassembling and calibrating it did the job.
Here are some models:
http://www.ebay.com/sch/Pocket-Digital-Scales-/163827/i.html
Even if you are doubtful as to the accuracy and precision of such scales, the price justifies buying one for testing.

[Edited on 20-2-2014 by Nickdul]

ZIGZIGLAR - 20-2-2014 at 15:08

I second what Nickdul has said. For an accuracy of 0.01g, eBay Jewellery scales are the go. Just make sure you calibrate it, as Nick said. For 0.001g, you're going to need to increase your budget dramatically, as even air movement can have a dramatic impact on accuracy, so eBay cheapos are likely to be a complete waste of money vs Jewellers scales.

Mailinmypocket - 20-2-2014 at 15:43

A while back I decided "what the hell" and spent 50$ on a milligram scale on eBay. It needs to be calibrated before each use and leveled with the fish eye level. Usually it has a +\- accuracy of .003g. Here is the accuracy of it today without calibration, still not horrible for a made in china 50$ milligram scale.

The result of weighing standard Ohaus calibration weights (100mg, 1g, 10g). Its good for getting a ballpark range for milligrams but I wouldn't rely on it entirely for very sensitive reactions of when you weigh valuable compounds. It also isn't as sensitive when adding or removing small amounts of material once it settled on a weight, which is more concerning. You can easily intend to add 30mg but the display jumps up to a different value after about 60mg has been added. I have found the 0.00g cheap scales to be more sensitive in that respect.

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hyfalcon - 20-2-2014 at 15:44

Notice, you get into quit a bit more money when you have to have real precision weights.

http://www.ebay.com/sch/i.html?_odkw=scale&_osacat=11815...

ZIGZIGLAR - 20-2-2014 at 17:58

You can get Digitial Scales like this with wind shield etc if you shop around. The calibration weights are often more expensive than the scales, aren't they haha

Mailinmypocket - 20-2-2014 at 18:10

This is the exact set I bought, albeit for about 10$ more. Highly useful though.
http://www.ebay.com/itm/271406485959?redirect=mobile

Nickdul - 20-2-2014 at 21:35

What Mailinmypocket says corroborates my personal experiences and for a beginner, I think this is the way to go.