Nope, no ballpark. They eyeball is the best measure of this for color developer and fix. The solutions begin to discolor rather rapidly and once the color developer concentrate goes beyond the color of tea to look like coffee it is done for. The reversal bath shows no change, it just stops working, and the same may be true of the first developer. The fix begins to get yellow particles precipitate out.
OK, thanks, Ron. I'm going to try my question a different way in a new thread with a new title.