The same controller can actuate equipment based on pH or oxidation reduction potential (ORP). Attach pH and ORP sensors (not included) and set the current measurement type with the selection switch. Controllers turn equipment on or off when the reading reaches the actuation point. They have one control relay and two alarm relays. Relays are SPDT (single pole, double throw) and can be set to turn one circuit from “off” to “on” (normally open) or from “on” to “off” (normally closed). Automatic temperature compensation standardizes readings at 77° F to prevent inaccurate results in fluctuating temperatures.

Controller with LED display is more visible in low-light conditions than controller with LCD display.