----- Original Message ----- From: "J. C. O'Connell"
Subject: RE: Decisions...Decisions...
One of the beauties of using 85 deg processing is that since it is only about 12 degrees above room temperture, there is much less drift in the process temp vs. time in an untempered process. With 100 deg processing the drift would be much more of a problem.
A good point to bring into the discussion is more on temperature drift.
Back in the dark ages, if we wanted to hit a median temperature of (eg:)85�F, we would measure how much the temperature of an untempered tank drifts down during the development cycle, halve that number and increase the starting temp by that amount.
In practice, if the drift over 6.5 minutes is 8�f, then the tank temperature to start would be raised to 89�F.
This completely obviates the need for any temperature control, providing the temperature drift is reasonable.
The only "trick" is I built the intermittant agitation timer myself which is a timed relay to turn motor on only 5 seconds out of every 30 seconds. But I think you could do second step with constant agitation too with same results so intermittant roller timer really isnt necessary...
You can use constant agititation during blix and wash as well.
William Robb
