Link This |
Email this |
Blog This |
Comments (0)
What is the importance of measuring conductivity?
July 2, 2007
Sponsored by
Question: My lead pressman tells me we should be paying more attention to conductivity. Why is measuring it so important?
Monitoring solution mixture
Conductivity is an important process-control parameter for the fountain or dampening solution used in offset lithographic printing. It indicates if the initial solution was mixed correctly with the proper dosage or concentration of chemicals, and whether the solution has changed significantly during its usage on press.
More important than pH today
Conductivity is probably a more important metric than pH because today’s fountain solutions are heavily buffered to a constant pH value and won’t vary much. However, conductivity will change as more or less chemical or contaminates are added or removed from the dampening solution.
What to watch for
The target value depends on your incoming water supply and treatment method. However, a tolerance of +/- 500 micromhos is often used. Low conductivity means the solution is weaker, similar to water. This may cause scumming problems. High conductivity means the solution is stronger or contaminated with paper or ink. If it’s due to too much etch, then plate blinding, blanket glazing and roller stripping may occur over extended periods of time.
Posted by Mark Vruno on July 2, 2007 | Comments (0)
