This will be our 3rd full summer for our fiberglass pool. I have the Hayward Sense & Dispense. Each spring I have had to make a minor recalibration adjustment to the pH sensor (typically .1 - .2) after doing several tests. In past springs, the ORP sensor gave what seemed like reasonable readings based on FC, pH, CYA, TA, and temperature. This year I am skeptical of the ORP readings I am getting. So, I am wondering if the ORP sensor could be going bad.
Are there any specific symptoms that would indicate the ORP sensor is going bad? Does it just stop giving readings? Does it get stuck on one value?
Also, if I have all my pool readings (like I mentioned above), is it possible to calculate what the ORP is? If it is complex math (too many years since calculus ), are there charts which show ORP based on pool readings?