[Alt-photo] HT-2 residual hypo test
gjh at shaw.ca
Sat Aug 5 17:46:44 UTC 2017
>From Facts and Formula's
Distilled water 180cc
Potassium permagnate 0.3 g
Sodium hydroxide 0.6 g
distilled water to make 250cc
take 250cc of pure water in a clear glass and add 1 cc of test solution. Then take one 8x10" film or plate from the wash water and allo the water to drip for 30 seconds from its surface into the galss containing the test solution.
If a small percentage of hype is present the violet color will change to orange in about 30 seconds. with larger concentrations of hype the orange color witll change to yellow.
when no change in the violet color occurs this indicates that the hype content has been reduced to a safe margin.
oxided organic matter in the water reacts and chnages the color in the same manner. test tap water alone and see if color changes, using same volume of water from paper. Note color change. If hypo from paper is present color will change more.
Gordon J. Holtslander
gjh at shaw.ca
Learn about HSP http://sp-foundation.org
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Sent: Saturday, August 5, 2017 11:06:38 AM
Subject: [Alt-photo] HT-2 residual hypo test
I am looking for a test chart that Kodak used to sell with the HT-2 residual hypo test that quantifies the amount of thiosulfate in the paper. This was used in the B&W days to test for washing of the prints. I am trying to be more scientific about my salted paper printing.
Does anybody have such a chart and could scan it for me.
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