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  for Metal Finishing since 1989
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Automatic pH measurement in nickel electroplating tank

We want to place a pH probe in our nickel plating tank to consistently measure the pH, but I am wondering if the electrical current in the tank will interfere with the probe. It seems like we tried this before and the probe read some wild results. Currently we are using pH paper to check pH and we need an automated system. Is there a "best" location to place a probe in the tank?

Chris Ballew
- Newport, Tennessee

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If the pH probe is in the way of the current path, you will get wild results. You may try to locate you probe in a mother tank that doesn't contain the anode or cathode bar. I find myself that nickel baths have a fairly stable pH, and never seen a need for on-line monitoring

Karl Weyermann
- Lebanon, Kentucky

The best place for the probe os out of the tank. If you are running some type of recirculation/filtration in the system, place an in-line pH probe in CPVC piping on the discharge side of the filter system. This keeps the probe isolated physically from the electrolyte current path. Also, the non-metallic piping discourages stray currents from upsetting your probe.

Charles R. Reichert CEF-SE
- Seattle, Washington