N2O UniAmp
Designed for research applications within:
Environmental Sciences
Biomedical Sciences

N2O microsensor

Measure dissolved and gaseous N2O

With a detection limit of less than 0.5 µM and tip sizes down to 25 µm, you can apply the N2O microsensor in any research application with the aim of measuring dissolved and gaseous N2O. Read more...

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Technical Data
Ordering Information & Sizes
Manuals & Videos
N2O Microsensor

N2O measurement technology

The Unisense nitrous oxide microsensor is a miniaturized Clark-type sensor with an internal reference and a guard cathode. In addition, the sensor is equipped with an oxygen front guard, which prevents oxygen from interfering with the nitrous oxide measurements.

The N2O-R sensor is a more robust version of the normal nitrous oxide sensor with optimized sensitivity and protection cap suited for bulk measurements including wastewater applications.

The sensor is connected to a high sensitivity picoammeter and the cathode is polarized against the internal reference. Driven by the external partial pressure, nitrous oxide from the environment will penetrate through the sensor tip membrane and be reduced at the metal cathode surface. The picoammeter converts the resulting current to a signal. The internal guard cathode is also polarized and scavenges N2O in the electrolyte, thus minimizing zero-current and polarization time.

For special applications, some versions of the N2O microsensor can be customized to have extremely high sensitivity (25 nM). Please see Technical Data.

N2O-R 2_1400x800

Patent information

This product is covered by the following patents:

Patent issued in China: CN 104937405 A

Patent issued in USA: 9921178

Patent issued in Japan: JP6275744B2

Patent issued in European EP Region: EP2939012B1

Patent pending in several other jurisdictions.

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Cables & Connectors
Stirring Sensitivity & Response Time
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 <2 mm 20%
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 130-160 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 adapter Yes, order separately
In situ gold pin connector No Yes 10%
Attribute Standard Options Extra price for option selection
Guaranteed lifetime 2 months
Expected lifetime 3-4 months
Expected lifetime N2O-R 4-6 months
Temperature range -10-50°C
Temperature range tip -10-50°C
Temperature coefficient 2-3 % per °C
Range Up to 500 µM in water Up to 28mM (1 atm p N2O) 20%
Detection limit N2O-50 0.3 µM in water
Detection limit N2O-100 0.1 µM in water
Detection limit N2O-500 0.1 µM in water <25 nM 20%
Detection limit N2O-R 0.1 µM in water <25 nM 20%
Detection limit N2O-MR 0.1 µM in water <25 nM 20%
Detection limit N2O-NP 0.1 µM in water
Internal reference Yes
Internal guard Yes
Waterproof Yes
Pressure compensation No
Spatial resolution Equals outside tip diameter
Response Linear
Known interferences NO | H2S | CO2: High (millimolar range) conc. of dissolved gaseous CO2 potentially affect base line signal.
Stirring Sensitivity & Response Time
N2O Stirring Sensitivity Response Time (90%)
N2O-50 | N2O-100 | N2O-500 <2% <20 s
N2O-R | N2O-MR | N2O-NP <2% <45 s
Ordering information & Sizes
Ordering information & Sizes
Nitrous Oxide Sensor Size and description Options Extra price for option selection
N2O-50 40-60 µm - glass sensor N2O-25 (25-35 µm) 10%
N2O-100 90-110 µm - glass sensor
N2O-500 400-600 µm - glass sensor
N2O-R 400-600 µm - with cap - glass sensor
N2O-MR 400-600 µm - in guide
N2O-NP 1.6 x 40 mm - needle sensor for piercing
N2O-ST-1/4 1/4'' steel tube
N2O-SL-1/4 FT-cell 1/4'' Swagelok Tee
N2O-SL-1/8 FT-cell 1/8'' Swagelok Tee
N2O-PEEK-1/8 FT-cell 1/8'' PEEK Tee
N2O-PEEK-1/16 FT-cell 1/16'' PEEK Tee
N2O-FT-GLASS-6 Glass FT-cell 6mm outer diameter
N2O-FT-GLASS-8 Glass FT-cell 8mm outer diameter

Video Guides

Quick Guide N2O Microsensors

We guide you through how the sensors are made, how you can apply them as well as specifications and customizations

N2O Calibration Kit Video

Application Scientist Tage Dalsgaard shows you how to perform a 2-point calibration with one zero N2O and one known N2O concentration

Are you looking for the Unisense Environment N2O Wastewater System?

Click here to go to www.unisense-environment.com.

Related publications

Dynamics of nitric oxide and nitrous oxide emission during full-scale reject water treatment
Kampschreur, Marlies J. et all (2008), Water Research, vol. 42, 812-826
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The earthworm gut: An ideal habitat for ingested N2O-producing microorganisms
Horn, Marcus A. et all (2003), Applied and Environmental Microbiology, vol. 69, 1662-1669
Read more
Development of a 2-sludge, 3-stage system for nitrogen and phosphorous removal from nutrient-rich wastewa⁠…
Zhou, Yan et all (2008), Water Research, vol. 42, 3207-3217
Read more
High nitrous oxide production from thawing permafrost
Elberling, Bo et all (2010), Nature Geoscience, vol. 3, 332-335
Read more