On Fri, 25 Apr 2003 20:36:24 -0400, James Ervin
wrote:

Help.

snip

So, have I got a bad pH monitor, bad probe or something else? I am
stumped. I suspect the controller is bad and is unable to fire the
solenoid and exibits the bad effects in the ramped up readings.

Hi,

One issue that you may investigate is if you are running electronic
ballasts, you MUST keep the pH sensor wiring (and anything else
electronic) away from them, the tubes and the wiring. The high
frequencies they operate will radiate into surrounding wiring and
effect the accuracy of the units.

I have witnessed this effect on both pH and temperature sensors and
their associated wiring in close proximity to switching ballasts.

One other factor to consider is whether the power supply of the pH
controller has enough (milli)amperage to handle the current draw of
the solenoid.

Greg