Lenn,
I believe the following suggestions are applicable regardless of the plate type:
- the developer pH must be kept constant throughout its expected lifetime as per manufacturer's specifications. Most problems come from too large production variability, if your plate processor will be idle - or worse, shut off - for long time the pH drops down. If your processor is new/just installed, you should monitor its pH up in the dev section, at correct temperature once a day and write this down in a logbook. The tech guy will know how to adjust the replenish and antiox rates to better suit your needs. Both antiox params are important operational volume and idle - machine sleeping.
- always measure pH at correct dev temperature. Remember to calibrate your pH-meter once a week at least. Read the pH-meter instructions carefully, the electrode must sit in a so-called storage solution (or pH 7, or distilled water) and never allowed to dry out, keep at least one bottle of reference solutions 7.00 and 10.00 handy to help you calibrate the device. This is imperative, as an uncalibrated meter is worse than not using one at all.
- Never operate your processors with top cover off to avoid dev coming in contact with ambient air
- you can use fresh dev as reference instead of reference pH solutions
- some manufacturers insist on pH more than others. Don't exceed chemistry change intervals. The dev filter being used is important I've seen someone using no name filters 15 micron instead of 50 as recommended and clogged up very early he didn't notice.
- check dev replenish pump and keep its valves clean
Ask your plate supplier for details. If you can't keep your processing conditions constant, why bother calibrating and linearizing your platesetter.
