(no subject)

I would like to make a correction to my statement below:

The molecular mass of ammonium dichromate is ~ 294, potassium dichromate
is ~ 252.

So, you have to use 294 / 252 = 16.6% more ammonium dichromate in order
to have a solution that has the same amnt. of dichromate ions as
potassium dichromate.

In other words, if you were using a 13% pot. di. solution, then you
have to mix a 13 x 1.16 ~= 15% soln. of amm. di. to have equivalent
amnt. of dichromate ions in solution (= exactly same contrast
character).

Anyway, I'm not sure one could tell the difference between the working
character of 13% amm. di. and 15% amm. di. So, you can also choose to
mix your amm. di. according the not-exactly-correct explanation below to
keep things a little bit simplier.

Hope this helps,
Loris.

-----Original Message-----
From: Loris Medici [mailto:loris_medici@mynet.com]
Sent: 12 Eylül 2005 Pazartesi 07:45
To: alt-photo-process-l@sask.usask.ca
Subject: RE:

Maria,

If you want to have the "same contrast properties" as your potassium
dichromate solution, make an ammonium dichromate solution at the "same
strength". If you're using a saturated Pot. Di. solution and not sure
about it strength: ...should be around 10% - %13. Keeping and mixing is
no different from Pot. Di.

Regards,
Loris.
Received on Mon Sep 12 01:59:40 2005