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

Highly sensitive hydrogen microsensor for gas and liquid measurements

The hydrogen microsensor offers you extraordinary sensitivity for reliable hydrogen measurement, even in natural systems and in gas. 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
Feature
Total length
Standard
150-200 mm
Options
70-350 mm
Extra price for option selection
20-50%
Feature
Diameter 20 mm from tip
Standard
< 2 mm
Options
< 1 mm
Extra price for option selection
10%
Feature
Glass shaft diameter
Standard
8 mm
Feature
Plastic shaft protection diameter*
Standard
11 mm
Options
Can be omitted
Extra price for option selection

*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
Item
Cable
Standard
Habia
Item
Cable length
Standard
1.5-2 m
Options
0-10 m
Extra price for option selection
Yes, depends on length
Item
Connector
Standard
LEMO
Options
BNC adaptor
Extra price for option selection
Yes, order separately
Item
In situ gold pin connector*
Standard
No
Options
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
Attribute
Guaranteed lifetime
Standard
3 months
Attribute
Expected lifetime
Standard
> 1 Year
Attribute
Temperature range
Standard
0-60°C
Attribute
Temperature coefficient
Standard
2-3% per °C
Attribute
Range
Standard
0-800 µM dissolved H2 (0-100% H2)
Options
High Range >800 µM
Extra price for option selection
20%
Attribute
Low Range sensors (LR)
Standard
0-240 µM (approx. 0-30% H2)
Attribute
Detection limit
Standard
0.3 µM in water
Options
< 50 nM (only for tip sizes ≥ 50 µm)
Extra price for option selection
10%
Attribute
Internal reference
Standard
Yes
Attribute
Waterproof
Standard
Yes
Attribute
Spatial resolution
Standard
Equals outside tip diameter
Attribute
Response
Standard
Linear
Attribute
Known interferences
Standard
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
Feature
Total length
Standard
150-200 mm
Options
70-350 mm
Extra price for option selection
20-50%
Feature
Diameter 20 mm from tip
Standard
< 4 mm
Feature
Glass shaft diameter
Standard
8 mm
Feature
Plastic shaft protection diameter*
Standard
11 mm
Options
Can be omitted
Extra price for option selection

*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
Item
Cable
Standard
Habia
Item
Cable length
Standard
1.5-2 m
Options
0-10 m
Extra price for option selection
Yes, depends on length
Item
Connector
Standard
LEMO
Options
BNC adaptor
Extra price for option selection
Yes, order separately
Item
In situ gold pin connector*
Standard
No
Options
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
Attribute
Guaranteed lifetime
Standard
3 months
Attribute
Expected lifetime
Standard
> 6 months
Attribute
Temperature range
Standard
0-50°C
Attribute
Temperature coefficient
Standard
2-3% per °C
Attribute
Range
Standard
0-800 µM dissolved H2 (0-100% H2)
Options
0-4000 µM dissolved H2 (0-400% H2)
Extra price for option selection
20%
Attribute
Low Range sensors (LR)
Standard
0-200 µM (approx. 0-25% H2)
Attribute
Detection limit
Standard
0.3 µM dissolved H2 (approx. 0.0375% H2)
Options
Low Range sensors (LR): < 50 nM dissolved H2 (approx. 0.00625% H2)
Extra price for option selection
10%
Attribute
Internal reference
Standard
Yes
Attribute
Waterproof
Standard
Yes
Attribute
Spatial resolution
Standard
Equals outside tip diameter
Attribute
Response
Standard
Linear
Attribute
H2S tolerance concentration range
Standard
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
H2-10
Stirring sensitivity
<2%
Response time (90%)
<10 s
Options
<0.3 sec for 10-100 µm tip sizes
Extra price for option selection
15%
H2
H2-25
Stirring sensitivity
<2%
Response time (90%)
<10 s
Options
<0.3 sec for 10-100 µm tip sizes
Extra price for option selection
15%
H2
H2-50
Stirring sensitivity
<2%
Response time (90%)
<10 s
Options
<0.3 sec for 10-100 µm tip sizes
Extra price for option selection
15%
H2
H2-100
Stirring sensitivity
<2%
Response time (90%)
<10 s
Options
<0.3 sec for 10-100 µm tip sizes
Extra price for option selection
15%
H2
H2-100LR*
Stirring sensitivity
Response time (90%)
<10 s
Options
<0.3 sec for 10-100 µm tip sizes
Extra price for option selection
15%
H2
H2-500
Stirring sensitivity
<2%
Response time (90%)
<10 s
H2
H2-500LR
Stirring sensitivity
Response time (90%)
<10 s
H2
H2-MR
Stirring sensitivity
<2%
Response time (90%)
<10 s
H2
H2-N
Stirring sensitivity
<2%
Response time (90%)
<10 s
H2
H2-NLR
Stirring sensitivity
Response time (90%)
<10 s
H2
H2-NP
Stirring sensitivity
<2%
Response time (90%)
<10 s
H2
H2-NPLR
Stirring sensitivity
Response time (90%)
<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
H2-X-50
Stirring sensitivity
<2%
Response time (90%)
<20 s
H2-X
H2-X-100
Stirring sensitivity
<2%
Response time (90%)
<20 s
H2-X
H2-X-100LR*
Stirring sensitivity
Response time (90%)
<30 s
H2-X
H2-X-500
Stirring sensitivity
<2%
Response time (90%)
<30 s
H2-X
H2-X-500LR
Stirring sensitivity
Response time (90%)
<30 s
H2-X
H2-X-MR
Stirring sensitivity
<2%
Response time (90%)
<30 s
H2-X
H2-X-MRLR
Stirring sensitivity
Response time (90%)
<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
H2-10
Size and description
8-12 µm - glass sensor
Options
3-5 µm
Extra price for option selection
20%
H2
H2-25
Size and description
20-30 µm - glass sensor
H2
H2-50
Size and description
40-60 µm - glass sensor
H2
H2-100
Size and description
90-110 µm - glass sensor
H2
H2-100LR
Size and description
90-110 µm - glass sensor
H2
H2-500
Size and description
400-600 µm - glass sensor
Options
100-400 µm
Extra price for option selection
20%
H2
H2-500LR
Size and description
400-600 µm - glass sensor - low range
H2
H2-MR
Size and description
400-600 µm - in guide
Options
600-800 µm
Extra price for option selection
20%
H2
H2-MRLR
Size and description
400-600 µm - in guide - low range
H2
H2-N
Size and description
1.1 x 40 mm - needle sensor
H2
H2-NLR
Size and description
1.1 x 40 mm - needle sensor - low range
H2
H2-NP
Size and description
1.6 x 40 mm - needle sensor for piercing
H2
H2-NPLR
Size and description
1.6 x 40 mm - needle sensor for piercing - low range
H2
H2-ST-1/4
Size and description
1/4'' steel tube
H2
H2-SL-1/4
Size and description
FT-cell 1/4'' Swagelok Tee
H2
H2-SL-1/8
Size and description
FT-cell 1/8'' Swagelok Tee
H2
H2-PEEK-1/8
Size and description
FT-cell 1/8'' PEEK Tee
H2
H2-PEEK-1/16
Size and description
FT-cell 1/16'' PEEK Tee
H2
H2-FT-GLASS-6
Size and description
Glass FT-cell 6mm outer diameter
H2
H2-FT-GLASS-8
Size and description
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
H2-X-50
Size and description
40-60 µm - H2S insensitive
Options
20-30 µm
Extra price for option selection
20%
H2-X
H2-X-100
Size and description
90-110 µm - H2S insensitive
H2-X
H2-X-100LR
Size and description
90-110 µm - H2S insensitive - low range
H2-X
H2-X-500
Size and description
400-600 µm - H2S insensitive
Options
200-400 µm
Extra price for option selection
20%
H2-X
H2-X-500LR
Size and description
400-600 µm - H2S insensitive - low range
H2-X
H2-X-MR
Size and description
400-600 µm - in guide - H2S insensitive
H2-X
H2-X-MRLR
Size and description
400-600 µm - in guide - H2S insensitive - low range
H2-X
H2-X-NP
Size and description
1.6 x 40 mm - needle sensor for piercing - H2S insensitive
H2-X
H2-X-NPLR
Size and description
1.6 x 40 mm - needle sensor for piercing - H2S insensitive - low range
H2-X
H2-X-ST-1/4
Size and description
1/4'' steel tube - H2S insensitive
H2-X
H2-X-SL-1/4
Size and description
FT-cell 1/4'' Swagelok Tee - H2S insensitive
H2-X
H2-X-SL-1/8
Size and description
FT-cell 1/8'' Swagelok Tee - H2S insensitive
H2-X
H2-X-PEEK-1/8
Size and description
FT-cell 1/8'' PEEK Tee - H2S insensitive
H2-X
H2-X-PEEK-1/16
Size and description
FT-cell 1/16'' PEEK Tee - H2S insensitive
H2-X
H2-X-FT-GLASS-6
Size and description
Glass FT-cell 6mm outer diameter - H2S insensitive
H2-X
H2-X-FT-GLASS-8
Size and description
Glass FT-cell 8mm outer diameter - H2S insensitive

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