Hydrogen Indicators | McMaster-Carr

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Hydrogen

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Warning: Products have one, but not necessarily all, of the selected characteristics.

	Scale Scale

	Pipe Size Pipe Size

1/8

1/4

1/2

	Thread Type Thread Type

NPT

	Measures Measures

Differential Pressure

Pressure

	Display Type Display Type

Digital

Color Band

U-Tube

	Maximum Pressure, psi Maximum Pressure, psi

	Connection Style Connection Style

	Connection Type Connection Type


Pipe	Tube

	Maximum Pressure Maximum Pressure

	Connection Location Connection Location

	Bottom		Center Back

	Minimum Pressure , psi Minimum Pressure , psi

	Gender Gender

Female

Male

	System of Measurement System of Measurement

Inch

	Dial Diameter Dial Diameter

1 3/4"

2 1/2"

	Accuracy Grade Accuracy Grade

Not Graded

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

DFARS Specialty Metals
COTS-Exempt

	Connection Material Connection Material

	Maximum Pressure, in. of H2O Maximum Pressure, in. of H2O

	Maximum Environment Temperature Maximum Environment Temperature

	Body Material Body Material

Stainless Steel

	Minimum Process Temperature Minimum Process Temperature

	Maximum Process Temperature Maximum Process Temperature

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35 Products

About Pressure Gauges

About Pipe Size

ABS Plastic Case With Center Back Connection

ABS Plastic Case
With Bottom
Connection

Bottom Connection

Center Back Connection

A four-digit LCD display allows for easy reading of measurements. The LCD shuts off automatically to extend battery life. Gauges are commonly used with pneumatic regulators, compressors, and in critical processes that require high accuracy, such as hydraulic and laboratory applications.

ABS Plastic Case with Brass Connection—(psi, bar, kg/cm², MPa)

For Use With: Air, Carbon Dioxide, Hydrogen, Nitrogen, Natural Gas
Accuracy: ±1% Full Scale (Grade 1A)

Available Pressure Ranges
Pressure Range
psi	bar	kg/cm²	MPa	Resolution, psi
0 to 145	0 to 10	0 to 10	0 to 1	0.1

							Center Back Connection
Dial Diameter	Pipe Size	Environment Temp. Range, °F	Process Temp. Range, °F	Batteries Included	Mounting Orientation	Features		Each
NPT Male
1 3/4"	1/8	-10° to 140°	-10° to 140°	Yes	Any	5-min. Automatic Shut-Off	000000	000000
1 3/4"	1/4	-10° to 140°	-10° to 140°	Yes	Any	5-min. Automatic Shut-Off	000000	00000

ABS Plastic Case with 304 Stainless Steel Connection—(psi, bar, MPa)

For Use With: Air, Hydrogen, Nitrogen
Accuracy: ±1% Full Scale (Not Graded)

Available Pressure Ranges
Pressure Range
psi	MPa	bar	Resolution, psi
0 to 30	0 to 0.2	0 to 2	0.01
0 to 100	0 to 0.7	0 to 6.9	0.1
0 to 300	0 to 2	0 to 20.7	0.1

							Bottom Connection
Dial Diameter	Pipe Size	Environment Temp. Range, °F	Process Temp. Range, °F	Batteries Included	Mounting Orientation	Features		Each
NPT Male
2 1/2"	1/4	0° to 185°	15° to 140°	Yes	Any	3-min. Automatic Shut-Off, Maximum Reading Recall	00000000	0000000
NPT Male with NIST Certificate
2 1/2"	1/4	0° to 185°	15° to 140°	Yes	Any	3-min. Automatic Shut-Off, Maximum Reading Recall	00000000	000000

Low-Pressure Differential Gauges with Color Indicator

A band of green, yellow, and red provides a clear indication of changes in differential pressure. Gauges are commonly used to indicate clogged filters.

For technical drawings and 3-D models, click on a part number.

Low-Pressure Differential Gauges with Color Indicator

For Use With: Air, Water, Hydraulic Fluid, Carbon Dioxide, Nitrogen, Hydrogen, Argon, and Acetylene
Accuracy: ±5% Full Scale (Not Graded)

	Pressure Range, psi
Pipe Size	Green Band	Yellow Band	Red Band	Max. Pressure, psi	Environment Temp. Range, °F	Process Temp. Range, °F	Ht.	Wd.	Dp.	Case Color		Each
NPT Female
1/4	0-2	2-2.5	2.5-3.5	300	-40° to 200°	-40° to 200°	3 1/4"	3 1/4"	1 1/2"	Black	0000000	000000
1/4	0-3	3-4.5	4.5-5	300	-40° to 200°	-40° to 200°	3 1/4"	3 1/4"	1 1/2"	Black	0000000	00000
1/4	0-6	6-9	9-12	300	-40° to 200°	-40° to 200°	3 1/4"	3 1/4"	1 1/2"	Black	0000000	00000
1/4	0-7.5	7.5-12	12-15	300	-40° to 200°	-40° to 200°	3 1/4"	3 1/4"	1 1/2"	Black	0000000	00000
1/4	0-13	13-20	20-30	300	-40° to 200°	-40° to 200°	3 1/4"	3 1/4"	1 1/2"	Black	0000000	00000
1/4	0-19.5	19.5-29.5	29.5-43	300	-40° to 200°	-40° to 200°	3 1/4"	3 1/4"	1 1/2"	Black	0000000	00000

Low-Pressure Differential Gauges with U-Tube

Also known as manometers, these gauges come with indicating liquid that moves up and down two columns—the difference in height between them is your pressure. They are commonly used to indicate clogged filters.

Magnet-mount gauges can be moved for use in multiple locations. Gauges with barbed tube connection have a flexible body that rolls up for storage or transport.

Nylon Plastic Connection—(in. of H₂O)

For Use With: Air, Argon, Carbon Dioxide, and Hydrogen
Accuracy: Not Rated (Not Graded)

With Barbed Tube Connection for 3/16" Tube ID
Pressure Range, in. of H₂O	Scale Range, in. of H₂O	Numeric Increments, in. of H₂O	Graduation Marks, in. of H₂O	Max. Pressure	Ht.	Max. Process Temp., °F	Gender	Mount Type		Each
0-8	4-0-4	1	0.1	Not Rated	17"	130°	Male	Magnet	0000000	0000000
0-12	6-0-6	1	0.1	Not Rated	21"	130°	Male	Magnet	0000000	000000
0-16	8-0-8	1	0.1	Not Rated	25"	130°	Male	Magnet	0000000	000000
0-24	12-0-12	1	0.1	Not Rated	33"	130°	Male	Magnet	0000000	000000
0-30	15-0-15	1	0.1	Not Rated	39"	130°	Male	Magnet	0000000	000000
0-36	18-0-18	1	0.1	Not Rated	45"	130°	Male	Magnet	0000000	000000
0-48	24-0-24	1	0.1	Not Rated	57"	130°	Male	Magnet	0000000	000000
0-60	30-0-30	1	0.1	Not Rated	69"	130°	Male	Magnet	0000000	000000
0-72	36-0-36	1	0.1	Not Rated	81"	130°	Male	Magnet	0000000	000000

Brass Connection—(in. of H₂O)

For Use With: Air, Argon, Carbon Dioxide, and Hydrogen
Accuracy: Not Rated (Not Graded)

With Compression Tube Connection for 1/4" Tube OD
Pressure Range, in. of H₂O	Scale Range, in. of H₂O	Numeric Increments, in. of H₂O	Graduation Marks, in. of H₂O	Max. Pressure, psi	Ht.	Gender	Mount Type		Each
0-8	4-0-4	1	0.1	100	20"	Female	Magnet	0000000	0000000
0-12	6-0-6	1	0.1	100	25"	Female	Magnet	0000000	000000
0-16	8-0-8	1	0.1	100	30"	Female	Magnet	0000000	000000
0-20	10-0-10	1	0.1	100	34"	Female	Magnet	0000000	000000
0-24	12-0-12	1	0.1	100	39"	Female	Magnet	0000000	000000
0-36	18-0-18	1	0.1	100	58"	Female	Magnet	0000000	000000

Sanitary Gauge Guards

Keeping corrosive substances from touching pressure gauges used in food-processing and pharmaceutical plants, these guards have a sanitary design. Made of 316 stainless steel, they won’t rust from frequent washdowns with harsh cleaners and sanitizers. They have continuously-welded seams and polished surfaces, so there aren’t any pits for bacteria to grow in. Removing them for cleaning and maintenance is easy thanks to their quick-clamp connection, which is sometimes called a tri-clamp.

Also known as isolators and diaphragm seals, these guards have a 316 stainless steel gasket to shield the pressure gauges from corrosion. Before use, fill the guards with fluid such as glycerin or silicone that’s suitable for food contact.

For technical drawings and 3-D models, click on a part number.

	Outlet Quick-Clamp Tube Connection
Inlet Pipe Connection	For Tube OD	Flange OD	Gasket Material	For Use With	Minimum Pressure, psi	Maximum Pressure	Maximum Temperature	Height	Interior Smoothness, Ra		Each
316 Stainless Steel Body
1/4 NPT Female	1 1/2"	1.984"	316 Stainless Steel	Acetylene, Air, Ammonia, Beverage, Boric Acid, Carbon Dioxide, Diesel Fuel, Ethanol, Food, Gasoline, Hydraulic Fluid, Hydrogen, Oxygen, Pharmaceuticals, Wastewater, Water	30	Not Rated	Not Rated	1 3/8"	32	0000000	0000000
1/4 NPT Female	2"	2.516"	316 Stainless Steel	Acetylene, Air, Ammonia, Beverage, Boric Acid, Carbon Dioxide, Diesel Fuel, Ethanol, Food, Gasoline, Hydraulic Fluid, Hydrogen, Oxygen, Pharmaceuticals, Wastewater, Water	30	Not Rated	Not Rated	1 1/8"	32	0000000	000000
1/2 NPT Female	1 1/2"	1.984"	316 Stainless Steel	Acetylene, Air, Ammonia, Beverage, Boric Acid, Carbon Dioxide, Diesel Fuel, Ethanol, Food, Gasoline, Hydraulic Fluid, Hydrogen, Oxygen, Pharmaceuticals, Wastewater, Water	30	Not Rated	Not Rated	1 3/8"	32	0000000	000000
1/2 NPT Female	2"	2.516"	316 Stainless Steel	Acetylene, Air, Ammonia, Beverage, Boric Acid, Carbon Dioxide, Diesel Fuel, Ethanol, Food, Gasoline, Hydraulic Fluid, Hydrogen, Oxygen, Pharmaceuticals, Wastewater, Water	30	Not Rated	Not Rated	1 1/8"	32	0000000	000000

Gauge Guards

316 Stainless Steel Guard

316 Stainless Steel Guard With Drain Port

Also known as isolators or diaphragm seals, these protect gauges from corrosive process media. Fill guards with ISO Grade 32 hydraulic oil (not included) before use.

316 stainless steel guards provide excellent corrosion and chemical resistance and can handle higher temperatures and pressures than plastic guards.

Guards with drain port allow you to remove process media.

For technical drawings and 3-D models, click on a part number.

Pipe Connections
Inlet	Outlet	Gasket Material	For Use With	Min. Pressure, psi	Max. Pressure	Max. Temp., °F	Ht.		Each
316 Stainless Steel Body
1/4 NPT Female	1/4 NPT Female	316 Stainless Steel	Acetylene, Air, Ammonia, Argon, Bleach, Boric Acid, Carbon Dioxide, Deionized Water, Diesel Fuel, Ethanol, Ethyl Alcohol, Gasoline, Hydraulic Fluid, Hydrogen, Liquid Nitrogen, Natural Gas, Nitrogen, Oxygen, Refrigerant, Salt Water, Steam, Water	60	2,500 psi @ 72° F	300°	1 1/2"	0000000	0000000
1/2 NPT Female	1/4 NPT Female	316 Stainless Steel	Acetylene, Air, Ammonia, Argon, Bleach, Boric Acid, Carbon Dioxide, Deionized Water, Diesel Fuel, Ethanol, Ethyl Alcohol, Gasoline, Hydraulic Fluid, Hydrogen, Liquid Nitrogen, Natural Gas, Nitrogen, Oxygen, Refrigerant, Salt Water, Steam, Water	60	2,500 psi @ 72° F	300°	1 1/2"	0000000	000000
1/2 NPT Female	1/2 NPT Female	316 Stainless Steel	Acetylene, Air, Ammonia, Argon, Bleach, Boric Acid, Carbon Dioxide, Deionized Water, Diesel Fuel, Ethanol, Ethyl Alcohol, Gasoline, Hydraulic Fluid, Hydrogen, Liquid Nitrogen, Natural Gas, Nitrogen, Oxygen, Refrigerant, Salt Water, Steam, Water	60	2,500 psi @ 72° F	300°	1 1/2"	0000000	000000
316 Stainless Steel Body with 1/4 NPT Female Drain Port
1/4 NPT Female	1/4 NPT Female	316 Stainless Steel	Acetylene, Air, Ammonia, Argon, Bleach, Boric Acid, Carbon Dioxide, Deionized Water, Diesel Fuel, Ethanol, Ethyl Alcohol, Gasoline, Hydraulic Fluid, Hydrogen, Liquid Nitrogen, Natural Gas, Nitrogen, Oxygen, Refrigerant, Salt Water, Steam, Water	60	2,500 psi @ 72° F	300°	2"	0000000	000000
1/2 NPT Female	1/4 NPT Female	316 Stainless Steel	Acetylene, Air, Ammonia, Argon, Bleach, Boric Acid, Carbon Dioxide, Deionized Water, Diesel Fuel, Ethanol, Ethyl Alcohol, Gasoline, Hydraulic Fluid, Hydrogen, Liquid Nitrogen, Natural Gas, Nitrogen, Oxygen, Refrigerant, Salt Water, Steam, Water	60	2,500 psi @ 72° F	300°	2"	0000000	000000
1/2 NPT Female	1/2 NPT Female	316 Stainless Steel	Acetylene, Air, Ammonia, Argon, Bleach, Boric Acid, Carbon Dioxide, Deionized Water, Diesel Fuel, Ethanol, Ethyl Alcohol, Gasoline, Hydraulic Fluid, Hydrogen, Liquid Nitrogen, Natural Gas, Nitrogen, Oxygen, Refrigerant, Salt Water, Steam, Water	60	2,500 psi @ 72° F	300°	2"	0000000	000000

About Pressure Gauges

About Pipe Size

Digital High-Accuracy Pressure Gauges

Low-Pressure Differential Gauges with Color Indicator

Low-Pressure Differential Gauges with U-Tube

Sanitary Gauge Guards

Gauge Guards