Cheap Digital ebay Scales for Measuring Chemistry

Discussion in 'Alternative Processes' started by kq6up, Mar 31, 2011.

  1. kq6up

    kq6up Member

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    Has anyone used one of the cheap scales on ebay? Are they accurate? I am getting into Alt. Processes, and I don't have a scale to measure chemistry. I don't want to break the bank getting all my supplies, and I was wondering if these are usable.

    Chris
     
  2. wildbill

    wildbill Member

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    I use a "my weigh" triton t2 from amazon.com. Cheap yes, accurate, yes, compact, yes. I just used cheap and accurate in the same sentence! Do a search if you need more on this as it has come up before.
     
  3. totalamateur

    totalamateur Member

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    Another source I've found for cheap, accurate scales are headshops. Ususally $15 - $25 will get you something that gets to .1 gram.

    Apparently Hookah connoissseurs really like to accruately measure their tobacco.
     
  4. kraker

    kraker Subscriber

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    Got mine from dealextreme. It has a tendency to "drift", hard to get a stable reading. Cheap, yes. Good? Good enough for measuring to an accuracy of 1 gram, but certainly nothing smaller...
     
  5. jeffreyg

    jeffreyg Subscriber

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    I have a Sunbeam digital postal scale that I bought at Office Depot. I checked it against a set of exact scientific weights and it is right on from 1 gram through 50 grams (8 different weights). It can be set to grams or ounces. I don't recall the price but I think it was in the $30 range.

    http://www.jeffreyglasser.com/
     
  6. kb3lms

    kb3lms Subscriber

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    I have one that I bought through Amazon but the same model was available on eBay. Measures up to 2kg, works great and is perfectly accurate as others here have mentioned. You should find it perfectly acceptable.
     
  7. pnance

    pnance Member

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    I found my Cent-o-gram scale (0.1 gram, $20) at a hamfest, if you always look around you never know what you'll find where. Kind of like taking pictures.

    Incidentally a hamfest is a amateur radio operator's flea market. Picked up a Leica iiic, also $20, at one last year. My dog described it as rough, rough. But the shutters good.
     
  8. michaelbsc

    michaelbsc Member

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    Just calibrate it. All you need are some standard weights, and for non-critical work those are a lot easier to get than most people realize.

    http://www.usmint.gov/about_the_mint/?action=coin_specifications

    Couple of bucks of coins and you're in business.

    I know this is US specific, but other countries have similar standards. I just don't know where to look for them. If you aren't in the US, try Google for finding the standard weights for your country's coins.

    If you need weights larger than your large coin, then weight 20 or 30 coins on the scale, discard any outliers, and measure a stack of them. For example, 20 US nickels would be 100g.

    Is it traceable to national standards and legal for retail trade? No, sorry.

    Is it more than good enough for a personal darkroom? Yes, you bet.

    The repeatability problem kraker reported would be the only deal breaker on a cheap scale, but most of the ones I've seen are extremely repeatable, and they're cheap enough to throw away and purchase new when they finally quit.

    MB
     
  9. Coffeehound

    Coffeehound Member

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    I just bought one of these (I am not the seller and I get nothing for this shameless plug). Only $9.99 and free shipping
    within the USA.... I will post information on the quality when it arrives.



    Digital Scale 500g x 0.1g Jewelry Gold Silver Coin Gram
    Item number: 3901739548674
    different weighing modes - g=grams, oz=ounces, dwt=pennyweight, ozt=troyounces

    500g capacity x 0.1g increments

    17.635oz capacity x 0.005oz increments

    321.5dwt capacity x 0.1dwt increments

    16.075ozt capacity x 0.005ozt increments

    Weighing tray measures 2 3/8" x 2 3/8"

    Scale measures 2 3/4" wide x 4" long x 3/4" thick

    Operates on 2 AAA Bateries included

    Scale has auto shut off after approx 2 minutes to save battery life

    SHIPPING

    Shipping is FREE to any US address using First Class mail. This service usually takes 2 to 5 business days for delivery. We ship no later than the next business day after your payment is received or clears. In many cases we ship the same day if paid early enough in the day.

    Shipping to Canada is by USPS Priority mail and will cost $11.95 which is the amount we pay our post office. All other countries shipping is $13.95using USPS Priority mail.

    Warranty: This scale has a two year warranty. If your scale ever fails with in two years of purchase just return it to me for a free replacement.
     
  10. Dan Dozer

    Dan Dozer Subscriber

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    I got mine on Ebay about two years ago and use it to weigh out the chemicals for Cyanotype. It was very cheap (I think only about $10 - $15) and it's made by NEVA. Has a calibration weight and has worked fine since I got it.
     
  11. lxdude

    lxdude Member

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    Geez you guys-what's wrong with an analog scale? I'm just sayin'...
    :tongue:
     
  12. kq6up

    kq6up Member

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    I don't think a triple beam could be had for $10.

    Chris
     
  13. Ross Chambers

    Ross Chambers Member

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    I bought a digital scale for something like $15 in the forecourt of a shopping mall, mainly as a standby for a more expensive one. It lasted about 2 months. The other probably still works, but I haven't used it since acquiring a "My Weigh" triple beam. I'm pleased to know that I can undertake a session without worrying about the electronic scale dying at the wrong time, the triple beam is something that will run forever.
     
  14. grahamp

    grahamp Subscriber

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    Digital scales are only readable to +/- half of the smallest unit. So 0.1g is 0.05g to 0.15g (assuming conventional rounding - the specs rarely say). It pays to have an extra step of display precision than you need for your project. Note that display precision and stability is not necessarily the same as accuracy or repeatability, or the precision of the weighing mechanism. Sensitivity of open pan balances is not usually a problem for air movement, but it can make the balance slower to respond. Stability/drift is usually a temperature issue. If you keep the balance at room temperature (in the room you weigh in) then only operational heat should be an issue.

    It is not as though we are weighing grams to 5 decimal places for general photographic purposes. When I was doing analytical chemistry, the 'bucket' lab only weighed to 0.1g, while the fine analytical weighing was done to 5 decimals (reported at 4), in a temperature controlled room using balances with integral draft shields.

    I have a small electronic unit. It is almost too small for photographic chemical volumes, so I usually have to tare off a pan. Think about this when you choose a model so that the display is readable. The specifications on these little things are usually bad - it is not always clear if taring comes out of the total capacity (assume it does). I have some domestic metric weights down to 5g, and some new coins, so I can test the unit from time to time. A good beam balance would be nice, but I don't have the need for it.
     
  15. Mainecoonmaniac

    Mainecoonmaniac Subscriber

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