Fountain Solution Conductivity

[Dr Who]

Umesh- good post.

Fount has an "operating window" in the UK it is between 2-4% in solution [giving the pH required], historically pH readings were used to make sure we were within the operating window. The advent of pH buffering agents destroyed this relationship as you could be at the pH you want but overdosing on concentrate, thus conductivity took its place as a way of measuring the % of fount in solution and when running as an indicator of contamination. Never seen figures as high as 10000, but your fount rep will set up the range for you, giving you figures for correct mix and an operating window before problems occur

 

[Nawab Ali]

Re: Fountain Solution Conductivity

Ernie,

Conductivity is a measurement for how much fountain concentrate to add to your press water system and monitor the changes during a press run to see how paper, alcohol or sub and ink may be affecting it. Let us say you are using a fountain concentrate that is buffered for Ph, in theory if you add one ounce or 9 ounces of the concentrate the Ph should not change, this is when conductivity comes into play. On your package of plates or your press manual or your ink supplier or your fountain concentrate they may recommend a certain range for Ph and conductivity and the meter will allow you to measure the water bottle to know how many ounces of concentrate to add. Let us say you measure your water source and it is 200uS and your plate vendor says our plates perform better at 1800uS. Add a little at time and measure until you reach the range they recommend. It is a tool to aid you in preparing fountain solution and keeping it consistent. Many big presses use chillers that monitor and change these problems.

OG

Did I can find TDS by ppm meter?

 

[Nawab Ali]

Re: Fountain Solution Conductivity

Ernie,

Conductivity is a measurement for how much fountain concentrate to add to your press water system and monitor the changes during a press run to see how paper, alcohol or sub and ink may be affecting it. Let us say you are using a fountain concentrate that is buffered for Ph, in theory if you add one ounce or 9 ounces of the concentrate the Ph should not change, this is when conductivity comes into play. On your package of plates or your press manual or your ink supplier or your fountain concentrate they may recommend a certain range for Ph and conductivity and the meter will allow you to measure the water bottle to know how many ounces of concentrate to add. Let us say you measure your water source and it is 200uS and your plate vendor says our plates perform better at 1800uS. Add a little at time and measure until you reach the range they recommend. It is a tool to aid you in preparing fountain solution and keeping it consistent. Many big presses use chillers that monitor and change these problems.

OG

Sir
I don't understand the relationship between each other of pH, conductivity and TDS.
I have some questions about this as under
1. What is the standard value of pH for offset printing?
2. What is the standard value of conductivity for offset printing and as TDS?
3. if damping water cross the maximum range of pH level, which Item will be add IPA or fountain for decrease the pH value?
4. If conductivity cross the the maximum range which item will be used further ?
5. What is the main character of IPA and Fountain in offset printing industry.

Your help and response will be highly appreciated

 

[Alois Senefelder]

Hello Nawab Ali


A PDF to help understand pH and Conductivity.


Regards, Alois

 

[Nawab Ali]

Hello Nawab Ali


A PDF to help understand pH and Conductivity.


Regards, Alois

Thanks a lot for response

 

[saso777]

Conductivity = μS/cm
Conductivity describes how electricity is conducted through a liquid; impurities in the dampening solution allow conductivity to increase. Conductivity varies depending on the water and additives. The temperature, and the concentration of alcohol also influence conductivity.

You can read more about conductivity and printing press chemistry here.