H2-500
MR sensor
Needle sensor
H2-X
fx-6 UniAmp
Designed for research applications within:
Environmental Sciences
Biomedical Sciences
Biotechnology
Photochemical water splitting
Effect of H2 enriched drinking water
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H2 microsensor

Highly sensitive hydrogen microsensor

The hydrogen microsensor offers you extraordinary sensitivity for reliable hydrogen measurement, even in natural systems. You will get a fast responding sensor, and you can choose a tip size down to 10 µm to achieve high spatial resolution. Read more...

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Technical Data
Stirring Sensitivity & Response Time
Ordering Information & Sizes
Adaptations
Manuals & Videos
H2 Microsensor

H2 measurement with or without H2S

H2S interferes with H2 measurements. For that reason, Unisense offers two types of hydrogen microsensors. If you are measuring in an H2S free environment, you can choose the standard type, H2.

If you want to measure in H2S containing environments, you should use the H2-X instead. This sensor has an H2S guard in the sensor tip that makes it insensitive to H2S up to 100 µM H2S or 1,000 ppm H2S in gas.

We can also make you a sensor with an even higher tolerance to H2S. Contact us for more information.

H2 Water splitting_700x400

Two types of hydrogen sensors

The two types of hydrogen sensors, H2 and H2-X, are used in the same way. The only differences between the two sensor types are that the H2-X tolerates H2S and has a slightly slower response.

The H2 and H2-X microsensors are Clark-type sensors measuring hydrogen partial pressure.

The working principle of the hydrogen microsensor is based on diffusion of hydrogen through a silicone rubber membrane in the tip to a platinum anode where the hydrogen gets oxidized. This anode is polarized against an internal reference electrode which receives the electrons from the oxidation of hydrogen at the platinum anode. The resulting current changes linearly with the hydrogen concentration at the sensor tip and is in the pA range. It is measured by a high quality picoammeter, such as the UniAmp amplifiers.

As hydrogen concentrations found in natural systems are generally very low, a low detection limit of the sensor is important. Generally, the detection limit of the sensors is close to 0.04% of hydrogen (0.3 µM in water) but with a larger tip membrane we can make the sensors even more sensitive, except for those with 10 µm and 25 µm tip diameter. Such low range sensors are more sensitive to stirring due to the larger analyte consumption rate. The H2 sensor can even be produced with an extreme sensitivity with a detection limit lower than 10 nM dissolved (approx. 0.00125%) H2. And as for all Unisense sensors, we can also make the H2 sensors for much higher H2 concentrations in pressurized systems.

H2 sensor tip_700x400 H2-X tip_700x400
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H2
H2-X
General
Cables & Connectors
Characteristics
General
Feature Standard Options Extra price for option selection
Total length 150-200 mm 70-350 mm 20-50%
Diameter 20 mm from tip < 2 mm < 1 mm 10%
Glass shaft diameter 8 mm
Plastic shaft protection diameter* 11 mm Can be omitted

*When mounted with in situ mini connectors, the shaft has no protection mounted, but fits directly into the in situ sensor mounts with pressure compensation. In situ sensors have a standard length of 140 mm ± 5 mm.

Cables & Connectors
Item Standard Options Extra price for option selection
Cable Habia
Cable length 1.5-2 m 0-20 m Yes, depends on length
Connector LEMO BNC adaptor Yes, order separately
In situ gold pin connector* No Yes

*When mounted with in situ mini connectors, the shaft has no protection mounted, but fits directly into the in situ sensor mounts with pressure compensation. In situ sensors have a standard length of 130-160 mm.

Characteristics
Attribute Standard Options Extra price for option selection
Guaranteed lifetime 3 months
Expected lifetime > 1 Year
Temperature range 0-60°C
Temperature coefficient 2-3% per °C
Range 0-800 µM dissolved H2 (0-100% H2) High Range >800 µM 20%
Range Low Range sensors (LR) 0-240 µM (approx. 0-30% H2)
Detection limit 0.3 µM in water <50 nM (only for tip sizes ≥ 50 µm) 10%
Internal reference Yes
Waterproof Yes
Spatial resolution Equals outside tip diameter
Response Linear
Known interferences Reduced volatile sulfur-containing substances, like H2S interfere strongly. Should not be used in anaerobic biological systems.
General
Cables & Connectors
Characteristics
General
Feature Standard Options Extra price for option selection
Total length 150-200 mm 70-350 mm 20-50%
Diameter 20 mm from tip <4 mm
Glass shaft diameter 8 mm
Plastic shaft protection diameter* 11 mm Can be omitted

*When mounted with in situ mini connectors, the shaft has no protection mounted, but fits directly into the in situ sensor mounts with pressure compensation. In situ sensors have a standard length of 140 mm ± 5 mm.

Cables & Connectors
Item Standard Options Extra price for option selection
Cable Habia
Cable length 1.5-2 m 0-20 m Yes, depends on length
Connector LEMO BNC adaptor Yes, order separately
In situ gold pin connector* No Yes

*When mounted with in situ mini connectors, the shaft has no protection mounted, but fits directly into the in situ sensor mounts with pressure compensation. In situ sensors have a standard length of 130-160 mm.

Characteristics
Attribute Standard Options Extra price for option selection
Guaranteed lifetime 3 months
Expected lifetime >6 months
Temperature range 0-50°C
Temperature coefficient 2-3% per °C
Range 0-800 µM dissolved H2 (0-100% H2) 0-4000 µM dissolved H2 (0-400% H2) 20%
Range Low Range sensors (LR) 0-200 µM (approx. 0-25% H2)
Detection limit 0.3 µM dissolved H2 (approx. 0.0375% H2) Low Range sensors (LR): <50 nM dissolved H2 (approx. 0.00625% H2) 10%
Internal reference Yes
Waterproof Yes
Spatial resolution Equals outside tip diameter
Response Linear
H2S tolerance concentration range 0-100 µM dissolved H2S, 1,000 ppm gas
H2
H2-X
Stirring Sensitivity & Response Time
Stirring Sensitivity & Response Time
H2 Stirring sensitivity Response time (90%) Options Extra price for option selection
H2-10 <2% <10 s <0.3 sec for 10-100 µm tip sizes 15%
H2-25 <2% <10 s <0.3 sec for 10-100 µm tip sizes 15%
H2-50 <2% <10 s <0.3 sec for 10-100 µm tip sizes 15%
H2-100 <2% <10 s <0.3 sec for 10-100 µm tip sizes 15%
H2-100LR* <10 s <0.3 sec for 10-100 µm tip sizes 15%
H2-500 <2% <10 s
H2-500LR <10 s
H2-MR <2% <10 s
H2-N <2% <10 s
H2-NLR <10 s
H2-NP <2% <10 s
H2-NPLR <10 s

*Low range sensors have more sensitivity to stirring due to the larger analyte consumption rate

Stirring Sensitivity & Response Time
Stirring Sensitivity & Response Time
H2-X Stirring sensitivity Response time (90%)
H2-X-50 <2% <20 s
H2-X-100 <2% <20 s
H2-X-100LR* <30 s
H2-X-500 <2% <30 s
H2-X-500LR <30 s
H2-X-MR <2% <30 s
H2-X-MRLR <30 s

*Low range sensors have more sensitivity to stirring due to the larger analyte consumption rate

H2
H2-X
Ordering information & Sizes
Ordering information & Sizes
H2 Size and description Options Extra price for option selection
H2-10 8-12 µm - glass sensor 3-5 µm 20%
H2-25 20-30 µm - glass sensor
H2-50 40-60 µm - glass sensor
H2-100 90-110 µm - glass sensor
H2-100LR 90-110 µm - glass sensor
H2-500 400-600 µm - glass sensor 100-400 µm 20%
H2-500LR 400-600 µm - glass sensor - low range
H2-MR 400-600 µm - in guide 600-800 µm 20%
H2-MRLR 400-600 µm - in guide - low range
H2-N 1.1 x 40 mm - needle sensor
H2-NLR 1.1 x 40 mm - needle sensor - low range
H2-NP 1.6 x 40 mm - needle sensor for piercing
H2-NPLR 1.6 x 40 mm - needle sensor for piercing - low range
H2-ST-1/4 1/4'' steel tube
H2-SL-1/4 FT-cell 1/4'' Swagelok Tee
H2-SL-1/8 FT-cell 1/8'' Swagelok Tee
H2-PEEK-1/8 FT-cell 1/8'' PEEK Tee
H2-PEEK-1/16 FT-cell 1/16'' PEEK Tee
H2-FT-GLASS-6 Glass FT-cell 6mm outer diameter
H2-FT-GLASS-8 Glass FT-cell 8mm outer diameter
Ordering information & Sizes
Ordering information & Sizes
H2-X Size and description Options Extra price for option selection
H2-X-50 40-60 µm - H2S insensitive 20-30 µm 20%
H2-X-100 90-110 µm - H2S insensitive
H2-X-100LR 90-110 µm - H2S insensitive - low range
H2-X-500 400-600 µm - H2S insensitive 200-400 µm 20%
H2-X-500LR 400-600 µm - H2S insensitive - low range
H2-X-MR 400-600 µm - in guide - H2S insensitive
H2-X-MRLR 400-600 µm - in guide - H2S insensitive - low range
H2-X-NP 1.6 x 40 mm - needle sensor for piercing - H2S insensitive
H2-X-NPLR 1.6 x 40 mm - needle sensor for piercing - H2S insensitive - low range
H2-X-ST-1/4 1/4'' steel tube - H2S insensitive
H2-X-SL-1/4 FT-cell 1/4'' Swagelok Tee - H2S insensitive
H2-X-SL-1/8 FT-cell 1/8'' Swagelok Tee - H2S insensitive
H2-X-PEEK-1/8 FT-cell 1/8'' PEEK Tee - H2S insensitive
H2-X-PEEK-1/16 FT-cell 1/16'' PEEK Tee - H2S insensitive
H2-X-FT-GLASS-6 Glass FT-cell 6mm outer diameter - H2S insensitive
H2-X-FT-GLASS-8 Glass FT-cell 8mm outer diameter - H2S insensitive

Related publications

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Oriented Films of Conjugated 2D Covalent Organic Frameworks as Photocathodes for Water Splitting
Sick, Torben et all (2018), Journal of the American Chemical Society, vol. 140, 2085-2092
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A Dye-Sensitized Photoelectrochemical Tandem Cell for Light Driven Hydrogen Production from Water
Sherman, Benjamin D. et all (2016), Journal of the American Chemical Society, vol. 138, 16745-16753
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02
Hydrogen from intestinal bacteria is protective for Concanavalin A-induced hepatitis
Kajiya, Mikihito et all (2009), Biochemical and Biophysical Research Communications, vol. 386, 316-321
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