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  1. #11
    Baxter Bradford's Avatar
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    Silverprint in UK sell the Salter 1250 diet scale (dearer than this quick search) http://www.rightonscales.com/web/1250.htm they have a max of 250g and accuracy of 0.1g

    I bought one for mixing B+W Pyrocat HD dev and it works very well. You can press the button to zero when adding succcessive chemicals to make your mathematical life easy!

  2. #12
    battra92's Avatar
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    Quote Originally Posted by David A. Goldfarb
    Good deals to be had at www.balances.com.
    A little Off Topic but I love the fact that there are "explosion proof" scales.

  3. #13
    Paul Sorensen's Avatar
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    Quote Originally Posted by battra92
    A little Off Topic but I love the fact that there are "explosion proof" scales.
    I love the term "intrinsically safe." What is the alternative, scales that are designed to cause bodily harm?

  4. #14
    edz
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    Quote Originally Posted by Neil Poulsen
    What are other scales that people use that are reasonably priced. What level of accuracy do I need? The amounts of chemistry can get pretty small, for example, when measuring amounts of the oxidizer to increase contrast.
    I'd suggest you keep an eye out for mechanical (pre-1980s) lab analytical balances . As digital has pushed the price of used darkroom gear into a black hole, digital balances have pushed (though changes in the demand and qualification of lab workers) them into the dumps. They are, while less convienient than the electronic models, just as acurate, better made and significantly more long term reliable. They probably sold for over $2000 USD 30-40 years ago which is real terms is many times the current price of state-of-the-art analytical balances. They resolve miligrams if not fractional miligrams-- and are more than sufficient for even phenidone or dimezone measurements.

    For less critical measures (and when you need to measure out more than 100g of something) there are some nice mechanical lab top-loaders also available for very little money. A baby scale is probably sufficient for most of these applications but in today's market I can imagine a good used mechanical baby scale would be more expensive and harder to find than a precision lab top-loader..
    Edward C. Zimmermann
    BSn R&D // http://www.nonmonotonic.net

  5. #15
    edz
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    Quote Originally Posted by battra92
    A little Off Topic but I love the fact that there are "explosion proof" scales.
    These are often mechanical. Electrical/electronic balances can create little charges (like micro-sparks) and these can be quite dangerous in explosive environments where such a "spark" can set off an explosion. This same logic applies to cameras and why fully mechanical cameras (including cine) continue to have their place.
    Edward C. Zimmermann
    BSn R&D // http://www.nonmonotonic.net

  6. #16
    Ole
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    Quote Originally Posted by Paul Sorensen
    I love the term "intrinsically safe." What is the alternative, scales that are designed to cause bodily harm?
    "Intrinsically Safe" has a very specific meaning, which you would appreciate if you ever had to work in a gas-filled atmosphere. I do once in a while, and IS is good.
    -- Ole Tjugen, Luddite Elitist
    Norway

  7. #17

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    I use an older mechanical triple-beam analytic scale. It was cheap at a garage sale. I think the guy that I bought it from was a retired drug dealer. It's really great for weighing chemicals. But I sweat profusely whenever my brother, the narcotics detective, visits because I can't figure out exactly what the odd residue on the scale's base is.

  8. #18

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    Linearity Studies

    Thanks for everyones' input. Based on the feedback, I'm leaning towards a couple of MyWeigh scales, one accurate to 0.005 gm with a 100gm capacity for smaller weights and a triple beam for weighing out larger amounts.

    Has anyone ever done a linearity study on these inexpensive scales by weighing sets of items and seeing if their collected weight equals the sum of their individual weights?

  9. #19

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    Neil,

    I have two scales, one with .1 gram accuracy and a capacity of 400g, and then other with a .01 gram accuracy with a capacity of 30g, if I remember correctly. The first is an electronic scale, and the second is a micro balance.

    I have to say that I sometimes wish I had larger capacity in the larger scale, because when I'm mixing PO or some other solutions in larger quantities, I have to measure some amounts in multiple steps, but that is a minor inconvienance.

    The smaller scale is a pocket sized balance. These are the preferred tool of the corner drug pusher because they are very accurate and easily transported. I almost never use it, except with a few formulas that requre a very small amount of a chemical (like pyrocat hd). Since I knew I wouldn't use it much at all, I couldn't justify getting a nice electronic scale, and these micro balances are very inexpensive as well, which is another reason they are favored by the drug crowd.

    For almost all the pt/pd chemicals (with the possible exception of chlorate for the A+B method of contrast control), a .1g accuracy scale is sufficient in my experience.

    As for calibration, I checked my scale with the calibration mass that came with it, and it was accurate to within .4g in 200g after being used for many years without calibration. I would not be too concerned about accuracy with a decent electronic scale, except in the very low end threshold region, where it may have some difficulty getting a precise, repeatable measurement. That's the best reason to have two scales with two different ranges and accuracy specifications.

    ---Michael
    www.mutmansky.com
    B&W photography in Silver, Palladium, and gum bichromate.

  10. #20

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    I used to own a Mettler P1200 top-loading analytical balance. I could weigh the condensation from my breath, a human hair, etc.

    It was a beautiful piece of equipment and I miss it dearly. It is absolute overkill but a joy to use. I paid about $40 for it on ebay and calibrated it using pocket change (yes I know, but it was good enough for me)

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