pH Probes | McMaster-Carr

	For Testing For Testing

Oxidation Reduction Potential
(ORP)

Conductivity

Total Dissolved Solids (TDS)

Resistivity

Chlorine

	For Use With For Use With

Dirty Liquids

Clean Liquids

	Mount Type Mount Type

Threaded

Hand Held

Panel

	Cable Length Cable Length

	pH Range pH Range

	Sensor Material Sensor Material

Glass

Nonglass

	Meter Type Meter Type

Direct Reading

Remote Reading

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

DFARS Specialty Metals
COTS-Exempt

	pH Accuracy pH Accuracy

±0.2 pH

±0.1 pH

±0.01 pH

	pH Resolution pH Resolution

0.01

0.1

	Display Display

LCD

LED

	Maximum Automatic Temperature Compensation (ATC) Maximum Automatic Temperature Compensation (ATC)

	Height Height

	Environment Environment

	Minimum Automatic Temperature Compensation (ATC) Minimum Automatic Temperature Compensation (ATC)

	Calibration Method Calibration Method

Button

Knob

	Battery Size Battery Size

AAA

CR2032

LR44

	Digit Height Digit Height

	Depth Depth

	Width Width

	Environmental Rating Environmental Rating

	Switch Configuration Switch Configuration

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

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

	Maximum Oxidation Reduction Potential (ORP) Maximum Oxidation Reduction Potential (ORP)

999 mV

1,000 mV

1,999 mV

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33 Products

Extended-Life Chemistry Sensors

Hand-Held Sensor

Threaded Sensor

The flat sensing tip resists deposit buildup and breakage for a long service life in harsh conditions. These sensors have a cable with a bayonet connection for compatibility with most chemistry meters and controllers.

Threaded sensors have an NPT male connection for installation in pipes and tanks.

Sensors with automatic temperature compensation standardize readings at 77° F to prevent inaccurate results in fluctuating temperatures.

For Testing pH
Mount Type (Connection)	Features	pH Range	Temp. Range, °F	Sensor Material	For Use With	Choose a Cable Lg., ft.		Each
Hand Held	__	0.0 to 13.0 pH	32° to 140°	Glass	Clean Liquids, Dirty Liquids	3, 10, 20	00000000	000000
Hand Held	Automatic Temperature Compensation	0.0 to 13.0 pH	32° to 140°	Glass	Clean Liquids, Dirty Liquids	3, 10, 20	00000000	000000
Threaded (NPT Male 3/4)	__	0.0 to 13.0 pH	32° to 140°	Glass	Clean Liquids, Dirty Liquids	10, 20	00000000	000000
Threaded (NPT Male 3/4)	Automatic Temperature Compensation	0.0 to 13.0 pH	32° to 140°	Glass	Clean Liquids, Dirty Liquids	10, 20	00000000	000000

Chemistry Sensors

Hand-Held Sensor

Threaded Sensor

A bayonet connection makes these sensors compatible with most chemistry meters and controllers.

Threaded sensors have an NPT male connection for installation in pipes and tanks.

Sensors with automatic temperature compensation standardize readings at 77° F to prevent inaccurate results in fluctuating temperatures.

For Testing pH

Mount Type (Connection)	Features	pH Range	Temp. Range, °F	Sensor Material	For Use With	Choose a Cable Lg., ft.		Each
Hand Held	__	0.0 to 12.0 pH	32° to 140°	Glass	Clean Liquids, Dirty Liquids	10	00000000	000000
Hand Held	__	0.0 to 14.0 pH	32° to 140°	Glass	Clean Liquids, Dirty Liquids	3, 20	00000000	00000
Hand Held	Automatic Temperature Compensation	0.0 to 12.0 pH	32° to 140°	Glass	Clean Liquids, Dirty Liquids	3, 10, 20	00000000	00000
Threaded (NPT Male 3/4)	__	0.0 to 12.0 pH	32° to 140°	Glass	Clean Liquids, Dirty Liquids	10, 20	00000000	000000
Threaded (NPT Male 3/4)	Automatic Temperature Compensation	0.0 to 12.0 pH	32° to 140°	Glass	Clean Liquids, Dirty Liquids	10, 20	00000000	000000

Water-Resistant pH Meters

Check pH in harsh field conditions. These floating meters that have a housing that meets IP67 for complete resistance to dust and protection from temporary submersion. Automatic temperature compensation standardizes readings at 77° F to prevent inaccurate results in fluctuating temperatures. Use a calibration solution and the calibration button to maintain accuracy. They do not include Calibration Solution. Meters cannot be sold to Canada due to import regulations.

Meter for clean liquids is commonly used in pools and hydroponic solutions.

Meter for dirty liquids stands up to wastewater, plating bath solutions, and other harsh liquids.

Meters
	pH									Replacement Sensors
Sensor Material	Range	Accuracy	Automatic Temperature Compensation (ATC) Range, °F	Environmental Rating	Specifications Met	Batteries Included	Cannot Be Sold To		Each		Each
For Use With Clean Liquids
Glass	0 to 14 pH	±0.1 pH	32° to 122°	IP67	CE Marked	Yes	Canada	00000000	000000	000000	00
For Use With Dirty Liquids
Glass	-2 to 16 pH	±0.01 pH	32° to 122°	IP67	CE Marked	Yes	Canada	00000000	00000	00000000	000000

pH Meters

More precise than test strips, these meters are often used to measure the pH of dirty liquids in agricultural systems, aquaculture tanks, and printing fountains. Automatic temperature compensation standardizes readings at 77° F to prevent inaccurate results in fluctuating temperatures. Use a Calibration Solution (not included) and the calibration button to maintain accuracy. Meters cannot be sold to Canada due to import regulations.

	pH
Sensor Material	Range	Accuracy	Automatic Temperature Compensation (ATC) Range, °F	Batteries Included	Cannot Be Sold To		Each
For Use With Dirty Liquids
Glass	0 to 14 pH	±0.1 pH	32° to 122°	Yes	Canada	0000000	000000

Remote-Reading pH Meters

Meter for Clean Liquids

Meter for Dirty Liquids

The remote sensor with a cable lets you take pH readings in hard-to-reach areas. Use a Calibration Solution and the calibration button to maintain accuracy. Meter for dirty liquids includes calibration solution; meter for clean liquids does not include calibration solution.

Nonglass sensors are more durable and resistant to breakage than glass sensors.

Meter for clean liquids is often used to check water quality.

Meter for dirty liquids stands up to use in petrochemical, environmental, and agricultural testing. The water-resistant housing meets IP65 for protection from dust and low-pressure washdowns. It cannot be sold to California due to energy regulations or to Canada due to import regulations.

Meters
	pH									Replacement Sensors
Sensor Material	Range	Accuracy	Automatic Temperature Compensation (ATC) Range, °F	Environmental Rating	Specifications Met	Batteries Included	Cannot Be Sold To		Each		Each
For Use With Clean Liquids
Glass	0 to 14 pH	±0.01 pH	32° to 212°	__	CE Marked	Yes	__	0000000	0000000	0000000	0000000
For Use With Dirty Liquids
Nonglass	0 to 14 pH	±0.01 pH	20° to 250°	IP65	CE Marked	Yes	CA, Canada	0000000	00000000	0000000	000000

Remote-Reading pH Meters with PC Output

Transmit pH readings to a PC for analysis. This meter has a sensor on a 3-ft. cable for taking remote readings of water and other clean liquids. It has automatic temperature compensation that standardizes readings at 77° F to prevent inaccurate readings in fluctuating temperatures. Use a Calibration Solution (not included) and the calibration button to maintain accuracy.

Meters
	pH							Replacement Sensors
Sensor Material	pH Range	Accuracy	Automatic Temperature Compensation (ATC) Range, °F	Specifications Met	Batteries Included		Each		Each
For Use With Clean Liquids
Glass	0 to 14 pH	±0.01 pH	14° to 212°	CE Marked	Yes	00000000	0000000	00000000	0000000

Easy-Read Bench-Top Multifunction Chemistry Meters

Don’t strain your eyes reading a scale—these bench-top meters indicate exact results on the digital display. For complete resistance to dust and protection from temporary submersion, these meters float and have a housing that meets NEMA 6 and IP67. They're for use with water and other clean liquids. Automatic temperature compensation standardizes readings at 77° F to prevent inaccurate results in fluctuating temperatures. Use a Calibration Solution (not included) and the calibration button to maintain accuracy.

Meters								Replacement Sensors
For Testing	Sensor Material	Automatic Temperature Compensation (ATC) Range, °F	Environmental Rating	Specifications Met	Batteries Included		Each		Each
For Use With Clean Liquids
Conductivity, Oxidation Reduction Potential (ORP), pH, Resistivity, Total Dissolved Solids (TDS)	Glass	32° to 160°	IP67, NEMA 6	CE Marked	Yes	000000	000000000	000000	0000000

Remote-Reading Multifunction Chemistry Meters

Remote sensors let you take pH and oxidation reduction potential (ORP) readings up to 3 feet from the display. For use with clean liquids, this meter is often used for water-quality testing. Automatic temperature compensation standardizes readings at 77° F to prevent inaccurate results in fluctuating temperatures. Use a Calibration Solution (not included) and the calibration button to maintain accuracy.

	pH		Oxidation Reduction Potential (ORP)
Sensor Material	Range	Accuracy	Range	Accuracy	Automatic Temperature Compensation (ATC) Range, °F	Specifications Met	Batteries Included		Each
For Use With Clean Liquids
Glass	0 to 14 pH	±0.01 pH	-1,000 to 1,000 mV	±2 mV	32° to 212°	CE Marked	Yes	0000000	0000000

Replacement sensor for testing Oxidation Reduction Potential (ORP)

0000000

Each

0000000

Remote-Reading Multifunction Chemistry Meters with PC Output

Upload up to 500 conductivity and total dissolved solids (TDS) readings to a PC. This meter has a probe on a 3-ft. cable for taking readings in hard-to-reach areas. It's for use with tap water, pool water, hydroponic solutions, and other clean liquids. Automatic temperature compensation standardizes readings at 77° F to prevent inaccurate results in fluctuating temperatures. Data hold freezes the current reading on the display. Use a Calibration Solution (not included) and the calibration button to maintain accuracy.

Meters
	Conductivity		Total Dissolved Solids (TDS)							Replacement Sensors
Sensor Material	Range	Accuracy	Range	Accuracy	Automatic Temperature Compensation (ATC) Range, °F	Specifications Met	Batteries Included		Each		Each
For Use With Clean Liquids
Nonglass	0 to 19.99 µS 0 to 199.9 µS 0 to 1,999 µS 0 to 19.99 mho 0 to 199.9 mho	±1%	0 to 9.99 ppm 10 to 99.9 ppm 100 to 999 ppm 1 to 9.99 ppt 10 to 99.9 ppt	±1%	-17° to 230°	CE Marked	Yes	00000000	0000000	00000000	0000000

Bench-Top Multifunction Chemistry Meters

Check the pH and conductivity of water and other clean liquids with one bench-top device. This meter has automatic temperature compensation that standardizes readings at 77° F to prevent inaccurate results in fluctuating temperatures. Use a Calibration Solution (not included) and the calibration knob to maintain accuracy.

Meters
	pH		Conductivity									Replacement Sensors
Sensor Material	Range	Accuracy	Range	Accuracy	Automatic Temperature Compensation (ATC) Range, °F	Ht.	Wd.	Dp.	Batteries Included		Each		Each
For Use With Clean Liquids
Glass	2-12 pH	±0.2 pH	0 to 10 µS 0 to 100 µS 0 to 1,000 µS 0 to 10,000 µS	±2%	50° to 160°	4"	3 1/2"	4 1/2"	Yes	00000000	0000000	00000000	0000000

Water-Resistant Multifunction Chemistry Meters

For Use with
Clean
Liquids

Test different water-chemistry measurements in dirty, wet conditions. Often used in pools and spas, all of these meters are for use with clean liquids. Automatic temperature compensation standardizes readings at 77° F to prevent inaccurate results in fluctuating temperatures. Use a calibration solution (not included) and the calibration button to maintain accuracy.

IP57 meters are protected from dust and temporary submersion in liquids.

Chlorine, oxidation reduction potential (ORP), and pH meters come with three sensors that each take one chemistry measurement. They cannot be sold to Canada due to import regulations.

For Testing Chlorine, Oxidation Reduction Potential (ORP), and pH

For Use With Clean Liquids
Sensor Material	Automatic Temperature Compensation (ATC) Range, °F	Environmental Rating	Specifications Met	Batteries Included	Cannot Be Sold To		Each
Glass	23° to 194°	IP57	CE Marked	Yes	Canada	0000000	0000000

Replacement Sensor for Testing pH	Each	000000
Replacement Sensor for Testing Chlorine	Each	000000
Replacement Sensor for Testing Oxidation Reduction Potential (ORP)	Each	00000

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