What do you think?

Tony · Post by **Tony** » Tue Jul 19, 2011 8:27 am

I am tempted to buy this on e-bay but wanted to know what any of the DCG gurus thought (if there are any out there still

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I was thinking of using it to check out film moisture (or dryness). I am thinking it was measuring the resistance between the probes. It may not be an absolute value but maybe a relative one. Using distilled water might mess things up and who knows what the gel or the AmDi will do to it, but it might be interesting. Maybe using a DVM would do the same thing??

http://cgi.ebay.com/LCD-Digital-Wood-Mo ... 23120de154

Any thoughts???

Dinesh · Post by **Dinesh** » Tue Jul 19, 2011 11:47 am

Well, one thought is that a typical emulsion is about 10 microns thick. Is this thick enough for the probes to read anything? Perhaps, you might try to throw a few crystals of (baked) desiccant, such as Cobalt Chloride, into the gelatin before you coat. The rate of colour change will give you an idea of the drying rate.

kyodai · Post by **kyodai** » Tue Jul 19, 2011 11:59 am

I have doubts that you would get any read out at all. A typical emulsion layer is just way too thin to really "dig" the electrodes into it deep enough to get proper contact. I fear you'd get the same readout as for thin air. besides you'd probably damage the emulsion trying to hold it tight against the film/plate.

Jeffrey Weil · Post by **Jeffrey Weil** » Tue Jul 19, 2011 12:25 pm

Here's the real kicker. Even if you did manage to get good contact with the gelatin, which I doubt could be done, the unit is calibrated for wood. Not emulsion's. Even if you did get a repeatable reading, it would be incorrect.

Jeff W

Tony · Post by **Tony** » Tue Jul 19, 2011 3:10 pm

Thanks all

Dinesh wrote:few crystals of (baked) desiccant, such as Cobalt Chloride

I think this is a good idea but I think to revert from pink (wet) to blue again it I think it needs to be baked out. I doubt if film sitting in an RH of 30-40% would be enough to turn it back to blue. They recconmend like 300 degrees for around an hour. But it might be worth a try. FYI I use a microwave on these guys and that works pretty well.

kyodai wrote:I have doubts that you would get any read out at all.

That might be true and I worried about this too. I think it is reading the resistance of water a few microns might not be enough to register. The good news its on glass and therefore the only thing to read is air and/or water. I would not measure center of the plate rather the edge.

Jeffrey Weil wrote:Even if you did manage to get good contact with the gelatin, which I doubt could be done, the unit is calibrated for wood

Yes very true, I would have used it as a relative reading, going from wet to dry. It is so hard to tell with DCG if film ready. Normally you just have to shoot it and pray.

Hey just a thought:)