Silver Gallon

Discussion in 'Silver Gelatin Based Emulsion Making & Coating' started by Kirk Keyes, Oct 24, 2008.

  1. Kirk Keyes

    Kirk Keyes Member

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    OK - I enjoy funky units, as long as I don't have to use them. So I have to ask, what's a "Silver Gallon"?
     
  2. Photo Engineer

    Photo Engineer Subscriber

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    Didn't your source explain it Kirk?

    At Kodak, we used a measure called a silver gallon. I never used it myself, but it was a funky measure of silver content in a raw melted emulsion. I myself used a more standard unit Kg of melt / mole of silver.

    PE
     
  3. Kirk Keyes

    Kirk Keyes Member

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    Well, I thought I would just toss that out there for whoever wanted to have fun with it.

    I see my Duffin book often uses "ripening volume" in ml melt/mole Ag. Probably very similar to your kg/mole Ag. Just the density difference between them.
     
  4. Photo Engineer

    Photo Engineer Subscriber

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    We found that due to variations, the only exact measure was to do an analysis of the emulsion to determine the silver content. However, Kg / mole eliminated the density variations inherent in volumetric measure.

    In any case, we developed a series of density equations for most everything including mixtures and temperature effects. This model helped us convert units handily to better than 0.01% from 20 - 40 deg C with things as diverse as NaBr/KI mixtures and AgNO3 up to 4 molar. It also included models for AgX.

    Ammonium Hydroxide, with a negative density profile was one of the more difficult as were many volatiles.

    PE
     
  5. Kirk Keyes

    Kirk Keyes Member

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    Is that something Kodak published, or could we get them to publish? It would be nice to have...
     
  6. bdial

    bdial Subscriber

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    It's the volume of silver a person can carry walking at a speed of 1 furlong/fortnight.:tongue:
     
  7. PhotoJim

    PhotoJim Member

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    Is a UK silver gallon larger than a US silver gallon? :smile:
     
  8. Photo Engineer

    Photo Engineer Subscriber

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    The equations are extremely complex. I was a member of the KP density standards committee that tested and verified the algorithms that did the calculations.

    I doubt if they would be interested in publication. In fact, you would need a rather complex computer program to implement the entire series of calculations.

    As for the US and Imperial silver gallon, :D , IDK if one ever existed. I never had to work with it. I worked with Kg/M.

    PE