pH Controllers | McMaster-Carr

	For Testing For Testing

Oxidation Reduction Potential
(ORP)

Conductivity

	Switch Configuration Switch Configuration

Turns "Off" to "On"
(Normally Open)

Turns "On" to "Off" (Normally
Closed)

	Display Display

LCD

LED

	Electrical Connection Type Electrical Connection Type

Bayonet

Screw Terminals

	Adjustment Method Adjustment Method

Digital Keypad

Button

	Current Current

	Depth Depth

2 1/2"

2 3/4"

4 3/4"

	DFARS (Defense Acquisition Regulations Supplement) DFARS (Defense Acquisition Regulations Supplement)

DFARS Specialty Metals
COTS-Exempt

	Fasteners Included Fasteners Included

Yes

	Industry Designation Industry Designation

SPDT

Single Pole, Single Throw
(SPST)

	Number of Control Relays Number of Control Relays

	Width Width

3 3/4"

	Mounting Location Mounting Location

Panel

Wall

	Maximum Conductivity Maximum Conductivity

	Conductivity Resolution Conductivity Resolution

0.001

0.01

0.1

	Minimum Conductivity Minimum Conductivity

7 Products

Multifunction Chemistry Controllers

LCD Display

LED Display

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 single pole, double throw (SPDT) 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.

	pH		Oxidation Reduction Potential (ORP)
DIN Trade Size	Range	Accuracy	Range	Accuracy	AC Voltage (Phase)	Mount Type	Ht.	Wd.	Dp.	Fasteners Included		Each
LCD Display
1/4	0.0 to 14.0 pH	±0.01 pH	-1,999 to 1,999mV	±0.1%	120 (Single)	Panel	3 3/4"	3 3/4"	4 3/4"	No	00000000	0000000
LED Display
1/4	0.0 to 14.0 pH	±0.01 pH	-1,999 to 1,999mV	±0.1%	120 (Single)	Panel	3 3/4"	3 3/4"	4 3/4"	No	00000000	000000

Chemistry Controllers

Controller

Adapter

Sensor

Turn pumps, mixers, valves, and other equipment on or off based on the pH or conductivity of a solution. These controllers compare input from a sensor (sold separately) to a programmed actuation point and turn equipment on or off when the reading reaches the actuation point. They have two control relays. Automatic temperature compensation standardizes readings at 77° F to prevent inaccurate results in fluctuating temperatures.

Controllers for testing pH also require an adapter.

For Testing pH

Controllers
pH													Sensors		Adapters
Range	Accuracy	Actuation Points	Actuation Tolerance	AC Voltage (Phase)	Ht.	Wd.	Dp.	Mounting Location	Mounting Hole Dia. (No. of)	Fasteners Included		Each		Each		Each
LCD Display
0.0 to 14.0 pH	±0.01 pH	2	0.00 to 1.00 pH	120 (Single)	3 3/4"	3 3/4"	2 3/4"	Panel, Wall	5mm (2)	Yes	00000000	0000000	000000000	0000000	000000000	000000

For Testing Conductivity

Controllers
Conductivity													Sensors
Range	Accuracy	Actuation Points	Actuation Tolerance	AC Voltage (Phase)	Ht.	Wd.	Dp.	Mounting Location	Mounting Hole Dia. (No. of)	Fasteners Included		Each		Each
LCD Display
0 to 2 µS 0 to 20 µS 0 to 200 µS 0 to 2,000 µS 0 to 20 mS 0 to 200 mS	±1%	2	0 to .2 µS 0 to 2 µS 0 to 20 µS 0 to 200 µS 0 to 2 mS 0 to 20 mS	120 (Single)	3 3/4"	5"	2 1/2"	Panel, Wall	5mm (2)	Yes	00000000	0000000	000000000	0000000