Measure pH of C41/E6 chemistry for viability?

[fotoobscura]

I have a pH meter I use for brewing and was wondering if there are 'known' pH levels for color chemistry that I could use to 'check' the viability of color developers and blix instead of risking a roll of film with exhausted or potentially contaminated chemistry..

Thanks

 

[Anon Ymous]

http://imaging.kodakalaris.com/sites/prod/files/files/resources/cis-61.pdf

 

[fotoobscura]

http://imaging.kodakalaris.com/sites/prod/files/files/resources/cis-61.pdf

Amazing. Thanks!

 

[Photo Engineer]

That being said, the pH is not a very reliable measure of the usefulness of a color developer. A developer can be totally dead, but have good color and pH.

PE

 

[fotoobscura]

PE,

Can you please expand upon that?. The way I'm reading the tech pub is that the pH is in fact a reliable way to measure the usefulness of a color developer. Are you talking specifically about if there's cross contamination or something?

FO

 

[Photo Engineer]

To meet aims of speed, contrast, fog and other image quality criteria, a strict adherence to the Kodak guidelines are needed for quality control. However, there are variations in the numerous control graphs showing what pH does outside of the exact "ideal". The pH value is one of these. However, a variation of + or - 0.01 or 0.02 pH units is not very significant in the face of a variation of + or - 0.1 or 0.2 g of developing agent, carbonate or hydroxyl amine. So, if the aim is 10.2 with a variation of 0.1, that means that 10.3 is good still, but then 10.4 is not bad.... See the chart for the results as pH varies and it can tell you the story better than this.

Try this for ECN, or look for the C41 version on the EK site: http://www.kodak.com/motion/Support...ocessing_Manuals/H24_Modules_Online/index.htm

But, pH is very difficult to actually define at the high salt content of the developer and must be measured at an exact temperature or by using a compensating electrode for both of these items.

PE