American Weigh Scale Scalemate Sm-501 Digital Pocket Scale, Silver, 500 X 0.01 G
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List Price: Our Price: $22.40 You Save: $20.55 (48%) Availability: Usually ships in 1-2 business days Category: Health Care See more product details |
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Customer Reviews of American Weigh Scale Scalemate Sm-501 Digital Pocket Scale, Silver, 500 X 0.01 G
Customer Review: Accurate for the price, but dishonest with multiples of 100 grams
Summary: 3 Stars
I've never owned a precision scale before, and I ordered this one for use in a science experiment. I also bought a 500 gram weight to calibrate it with (and also a 100 gram weight, for testing purposes).
This scale appears to have a repeatability within about 0.015 or 0.02 grams, which is probably quite good for the price. It has a brightly backlit display which is easily readable unless you're looking from an extremely steep angle. However, it is programmed with a dishonest "feature"; if it registers a weight within 0.04 grams of any multiple of 100 grams, it will "cheat" and round to the nearest 100. For example, anything registering in the range 99.96 to 100.04 grams will be "locked" to 100.00 grams, and anything from -0.04 to 0.04 grams will be locked to 0.00, etc. This is applied after your tare is subtracted (e.g., if the scale internally registers a total of 131.28 grams and your tare is 31.24 grams, the display will show 100.00 grams instead of 100.04). I tested every multiple of 100 (0.00, 100.00, 200.00, 300.00, 400.00, 500.00) using drops of water in a glass, and the SM-501 does the same thing for each. This issue can be worked around by adding a known weight and then subtracting it in your head, but this defeats the convenience of having a "tare" feature. On the other hand, if you'll never be weighing anything that's close to a multiple of 100 grams then it won't be a problem.
Customer Review: ok, buttons wear out
Summary: 3 Stars
Quite accurate, though I'm not sure it is 0.01g accurate, because I don't shield it from air movement. The pad is a bit small (2.5"x2.75"), and the tare button can easily be blocked if you try to weight using a container. Also, it is light and the feet aren't that grippy, so it is easily nudged astray. Finally, it *does* go out of calibration, so I check it once a month or so (good enough for my purposes...)
Regarding auto-zeroing small, slow weight additions, I understand that this is considered a feature for some reason. Like the others I don't know why this would be desirable. For precise measuring, you can gently press on the container or lift it up as you add/sub material. Either disturbs the scale out of that auto-zero mode.
Until now I have been satisfied with this scale - a great deal for 500g@0.01g. But after less than a year the buttons have started wearing out. I now have to firmly press and wiggle the power button to turn it on, and the tare button has started degrading as well. That is why I only gave it three stars.
Customer Review: It's worse that that...
Summary: 1 Stars
Thank you Ellsworth for an excellent review. Actually the error is worse than that. Try this experiment:
Cut a piece of paper into a 8" x 1" strip and weigh it. It will register about a half gram.
Remove the paper and snip a 1" x 1/4" strip with a pair of scissors and let it fall onto the scale. The scale will continue to register zero as Ellsworth predicts.
Continue cutting strips onto the scale once per second. The scale will continue to register zero for as long as you care to snip!
Customer Review: out2
Summary: 1 Stars
Unfortunately I've used it for only a month or so and it's no longer usable. An error code "out2" is displayed when you turn it on. The manual is talking about calibrating it but it can't be done. I never shocked or dropped the thing, and no one else has ever used it. I calibrated it with the standard 500g weigh as well so can only assume it's a bad product with a misleading manual.
It's just not worth it.