N2O microsensor with a 25 µm tip diameter. The yellowish part of the sensor tip is the oxygen front guard that makes the N2O sensor insensitive to oxygen.
For optimal protection of the glass sensor a protection cap can be mounted. This is a good solution for measurement in bulk water e.g. in wastewater applications.
The N2O microsensor signal must be amplified by a Unisense amplifier e.g. the N2O UniAmp
Designed for research applications within:
Wastewater
Environmental Sciences
Biomedical Sciences
Biotechnology
Microbiology
N2O Microsensor
Measure dissolved and gaseous nitrous oxide
With a detection limit of 0.1 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...
Manual
Read More
Technical Data
Ordering Information & Sizes
Customizations
Manuals & Videos
Quick Enquiry
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 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, we can customize the N2O microsensor to your needs in relation to the range and response time. Contact us or check the Technical Data.
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.
General
Cables & Connectors
Characteristics
Stirring Sensitivity & Response Time
General
| Feature | Standard | Options | Extra price for option selection |
|---|---|---|---|
|
Feature
Total length
|
Standard
150-200 mm
|
Options
200-350 mm
|
Extra price for option selection
20-50%
|
|
Feature
Diameter 20 mm from tip
|
Standard
<4 mm
|
Options
<2 mm
|
Extra price for option selection
20%
|
|
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 130-160 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 adapter
|
Extra price for option selection
Yes, order separately
|
|
Item
In situ gold pin connector
|
Standard
No
|
Options
Yes
|
Extra price for option selection
10%
|
Characteristics
| Attribute | Standard | Options | Extra price for option selection |
|---|---|---|---|
|
Attribute
Guaranteed lifetime
|
Standard
2 months
|
||
|
Attribute
Expected lifetime
|
Standard
3-4 months
|
||
|
Attribute
Expected lifetime N2O-R (LR/SR/IR/HR)*
|
Standard
4-6 months
|
||
|
Attribute
Temperature range
|
Standard
-10-50°C
|
||
|
Attribute
Temperature range tip
|
Standard
-10-50°C
|
||
|
Attribute
Temperature coefficient
|
Standard
2-3 % per °C
|
||
|
Attribute
Range N2O-50/100/500
|
Standard
Up to 200 µM
|
||
|
Attribute
Range N2O-R-SR
|
Standard
Up to 50 µM
|
Options
Up to 28 mM (1 atm pN2O)
|
Extra price for option selection
20%
|
|
Attribute
Range N2O-R-IR
|
Standard
Up to 300 µM
|
||
|
Attribute
Range N2O-R-HR
|
Standard
Up to 4 mM
|
||
|
Attribute
Range N2O-R-LR
|
Standard
Up to 10 µM
|
||
|
Attribute
Range N2O-MR/NP/FT/SL/ST/PEEK**
|
Standard
Up to 50 µM
|
Options
The -MR, -NP, -FT, -SL, -ST, and PEEK are also available as LR, IR, and HR.
|
Extra price for option selection
10%
|
|
Attribute
Detection limit N2O-50
|
Standard
0.3 µM in water
|
||
|
Attribute
Detection limit N2O-100
|
Standard
0.1 µM in water
|
||
|
Attribute
Detection limit N2O-500
|
Standard
0.1 µM in water
|
||
|
Attribute
Detection limit N2O-R-SR
|
Standard
0.1 µM in water
|
||
|
Attribute
Detection limit N2O-R-IR
|
Standard
0.3 µM in water
|
||
|
Attribute
Detection limit N2O-R-HR
|
Standard
1 µM in water
|
||
|
Attribute
Detection limit N2O-R-LR
|
Standard
25 nM in water
|
||
|
Attribute
Detection limit N2O-MR/NP/FT/SL/ST/PEEK
|
Standard
0.1 µM in water
|
||
|
Attribute
Internal reference
|
Standard
Yes
|
||
|
Attribute
Internal guard
|
Standard
Yes
|
||
|
Attribute
Waterproof
|
Standard
Yes
|
||
|
Attribute
Pressure compensation
|
Standard
No
|
||
|
Attribute
Spatial resolution
|
Standard
Equals outside tip diameter
|
||
|
Attribute
Response
|
Standard
Linear
|
||
|
Attribute
Known interferences
|
Standard
NO | H2S | CO2: High (millimolar range) conc. of dissolved gaseous CO2 potentially affect base line signal.
|
*LR = Low Range | SR = Standard Range | IR = Intermediate Range | HR = High Range
**Sensors must never be exposed to N2O concentrations above their measuring range.
Stirring Sensitivity & Response Time
| N2O | Stirring Sensitivity | Response Time (90%) |
|---|---|---|
|
N2O
N2O-50
|
Stirring Sensitivity
<2%
|
Response Time (90%)
<30 s
|
|
N2O
N2O-100
|
Stirring Sensitivity
<2%
|
Response Time (90%)
<30 s
|
|
N2O
N2O-500
|
Stirring Sensitivity
<2%
|
Response Time (90%)
<35 s
|
|
N2O
N2O-R (All variants)
|
Stirring Sensitivity
<2%
|
Response Time (90%)
<65 s
|
|
N2O
N2O-MR/NP/FT/SL/ST/PEEK
|
Stirring Sensitivity
<2%
|
Response Time (90%)
<65 s
|
Ordering information & Sizes
Ordering information & Sizes
| Nitrous Oxide Sensor | Size and description | Options | Extra price for option selection |
|---|---|---|---|
|
Nitrous Oxide Sensor
N2O-50
|
Size and description
40-60 µm - glass sensor
|
Options
N2O-25 (25-35 µm)
|
Extra price for option selection
10%
|
|
Nitrous Oxide Sensor
N2O-100
|
Size and description
90-110 µm - glass sensor
|
||
|
Nitrous Oxide Sensor
N2O-500
|
Size and description
400-600 µm - glass sensor
|
||
|
Nitrous Oxide Sensor
N2O-R-LR
|
Size and description
400-600 µm - with cap - glass sensor - Low Range*
|
||
|
Nitrous Oxide Sensor
N2O-R-SR
|
Size and description
400-600 µm - with cap - glass sensor - Standard Range*
|
||
|
Nitrous Oxide Sensor
N2O-R-IR
|
Size and description
400-600 µm - with cap - glass sensor - Intermediate Range*
|
||
|
Nitrous Oxide Sensor
N2O-R-HR
|
Size and description
400-600 µm - with cap - glass sensor - High Range*
|
||
|
Nitrous Oxide Sensor
N2O-MR
|
Size and description
400-600 µm - in guide
|
||
|
Nitrous Oxide Sensor
N2O-NP
|
Size and description
1.6 x 40 mm - needle sensor for piercing
|
||
|
Nitrous Oxide Sensor
N2O-ST-1/4
|
Size and description
1/4'' steel tube
|
||
|
Nitrous Oxide Sensor
N2O-SL-1/4
|
Size and description
FT-cell 1/4'' Swagelok Tee
|
||
|
Nitrous Oxide Sensor
N2O-SL-1/8
|
Size and description
FT-cell 1/8'' Swagelok Tee
|
||
|
Nitrous Oxide Sensor
N2O-PEEK-1/8
|
Size and description
FT-cell 1/8'' PEEK Tee
|
||
|
Nitrous Oxide Sensor
N2O-PEEK-1/16
|
Size and description
FT-cell 1/16'' PEEK Tee
|
||
|
Nitrous Oxide Sensor
N2O-FT-GLASS-6
|
Size and description
Glass FT-cell 6mm outer diameter
|
||
|
Nitrous Oxide Sensor
N2O-FT-GLASS-8
|
Size and description
Glass FT-cell 8mm outer diameter
|
*Stainless steel cap, 10 mm outer diameter. Stirring sensitivity for all types <2%.
The -MR, -NP, -FT, -SL, -ST, and PEEK are also available as LR, IR, and HR. This costs 10% extra for -MR and -NP.
Sensors must never be exposed to N2O concentrations above their measuring range.
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
Quick Enquiry
Are you looking for the Unisense Environment N2O Wastewater System?
Click here to go to www.unisense-environment.com.
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N2O
N2O Microsensor
Measure dissolved and gaseous nitrous oxide
NO
NO Microsensor
Measure minute concentrations of nitric oxide
pH
pH Microelectrode
Miniaturized pH electrode
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Redox Microelectrode
Measure redox potential in microenvironments
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Applications
Microbiology
Wastewater
Understanding the Denitrification Dynamics of Nitrifying Microorganisms
How nitrifying microorganisms are able to produce nitrous oxide through denitrification
Microbiology
Wastewater
Mitigation of N2O Emissions from Wastewater Biofilms
Mitigation of N2O Emissions from Wastewater Biofilms
Microbiology
Wastewater
Nitrogen Removal in Wastewater
The use of oxygen microelectrodes to study nitritation biofilms with different geometries
Microbiology
Biofilm – O2 and N2O Microprofiles in Samples from CF patients
O2 and N2O microprofiles in sputum samples from cystic fibrosis patients with chronic Pseudomonas aeruginosa lung infection
Related publications
Dynamics of nitric oxide and nitrous oxide emission during full-scale reject water treatment
Kampschreur, Marlies J. et al. (2008),
Water Research,
vol. 42,
812-826
Kampschreur, Marlies J., van der Star, Wouter R.L., Wielders, Hubert A., Mulder, Jan Willem, Jetten, Mike S.M., van Loosdrecht, Mark C.M. (2008),
Water Research,
vol.
42,
812-826
Emission of NO and N2O from a full-scale two-reactor nitritation-anammox process was determined during a measurement campaign at the Dokhaven-Sluisjesdijk municipal WWTP (Rotterdam, NL). The NO and N2O levels in the off-gas responded to the aeration cycles and the aeration rate of the nitritation reactor, and to the nitrite and dissolved oxygen concentration. Due to the strong fluctuations in the NO and N2O levels in both the nitritation and the anammox reactor, only time-dependent measurements could yield a reliable estimate of the overall NO and N2O emissions. The NO emission from the nitritation reactor was 0.2% of the nitrogen load and the N2O emission was 1.7%. The NO emission from the anammox reactor was determined to be 0.003% of the nitrogen load and the N2O emission was 0.6%. Emission of NO2 could not be detected from the nitritation-anammox system. Denitrification by ammonia-oxidizing bacteria was considered to be the most probable cause of NO and N2O emission from the nitritation reactor. Since anammox bacteria have not been shown to produce N2O under physiological conditions, it is also suspected that ammonia-oxidizing bacteria contribute most to N2O production in the anammox reactor. The source of NO production in the anammox reactor can be either anammox bacteria or denitrification by heterotrophs or ammonia-oxidizing bacteria. Based on the results and previous work, it seems that a low dissolved oxygen or a high nitrite concentration are the most likely cause of elevated NO and N2O emission by ammonia-oxidizing bacteria. The emission was compared with measurements at other reject water technologies and with the main line of the Dokhaven-Sluisjesdijk WWTP. The N2O emission levels in the reject water treatment seem to be in the same range as for the main stream of activated sludge processes. Preliminary measurements of the N2O emission from a one-reactor nitritation-anammox system indicate that the emission is lower than in two-reactor systems. © 2007 Elsevier Ltd. All rights reserved.
10.1016/j.watres.2007.08.022
Read more
The earthworm gut: An ideal habitat for ingested N2O-producing microorganisms
Horn, Marcus A. et al. (2003),
Applied and Environmental Microbiology,
vol. 69,
1662-1669
Horn, Marcus A., Schramm, Andreas, Drake, Harold L. (2003),
Applied and Environmental Microbiology,
vol.
69,
1662-1669
The in vivo production of nitrous oxide (N2O) by earthworms is due to their gut microbiota, and it is hypothesized that the microenvironment of the gut activates ingested N2O-producing soil bacteria. In situ measurement of N2O and O2 with microsensors demonstrated that the earthworm gut is anoxic and the site of N2O production. The gut had a pH of 6.9 and an average water content of approximately 50%. The water content within the gut decreased from the anterior end to the posterior end. In contrast, the concentration of N2O increased from the anterior end to the mid-gut region and then decreased along the posterior part of the gut. Compared to the soil in which worms lived and fed, the gut of the earthworm was highly enriched in total carbon, organic carbon, and total nitrogen and had a C/N ratio of 7 (compared to a C/N ratio of 12 in soil). The aqueous phase of gut contents contained up to 80 mM glucose and numerous compounds that were indicative of anaerobic metabolism, including up to 9 mM formate, 8 mM acetate, 3 mM lactate, and 2 mM succinate. Compared to the soil contents, nitrite and ammonium were enriched in the gut up to 10- and 100-fold, respectively. The production of N2O by soil was induced when the gut environment was simulated in anoxic microcosms for 24 h (the approximate time for passage of soil through the earthworm). Anoxia, high osmolarity, nitrite, and nitrate were the dominant factors that stimulated the production of N2O. Supplemental organic carbon had a very minimal stimulatory effect on the production of N2O, and addition of buffer or ammonium had essentially no effect on the initial N2O production rates. However, a combination of supplements yielded rates greater than that obtained mathematically for single supplements, suggesting that the maximum rates observed were due to synergistic effects of supplements. Collectively, these results indicate that the special microenvironment of the earthworm gut is ideally suited for N2O-producing bacteria and support the hypothesis that the in situ conditions of the earthworm gut activate ingested N2O-producing soil bacteria during gut passage.
10.1128/AEM.69.3.1662-1669.2003
Read more
Development of a 2-sludge, 3-stage system for nitrogen and phosphorous removal from nutrient-rich wastewa…
Zhou, Yan et al. (2008),
Water Research,
vol. 42,
3207-3217
Zhou, Yan, Pijuan, Maite, Yuan, Zhiguo (2008),
Water Research,
vol.
42,
3207-3217
A novel 2-sludge 3-stage process using a combination of granular sludge and biofilm was developed to achieve biological removal of nitrogen and phosphorus from nutrient-rich wastewater. The system consists of a granular sequencing batch reactor (SBR) working under alternating anaerobic/anoxic conditions supplemented with a short aerobic phase and an aerobic biofilm SBR. The wastewater is first fed to the granular SBR reactor, where easily biodegradable carbon sources are taken up primarily by polyphosphate accumulating organisms (PAOs). The supernatant resulting from quick settling of the granular sludge is then fed to the biofilm SBR for nitrification, which produces oxidized nitrogen that is returned to the granular reactor for simultaneous denitrification and phosphorus removal. While maximizing the utilization of organic substrates and reducing operational costs, as do other 2-sludge processes previously reported in literature, the proposed system solves the bottleneck problem of traditional 2-sludge systems, namely high effluent ammonia concentration, due to its high-volume exchange ratios. An ammonia oxidation rate of 32 mg N/L h was achieved in the biofilm SBR, which produced nitrite as the final product. This nitrite stream was found to cause major inhibition on the anoxic P uptake and also to result in the accumulation of N2O. These problems were solved by feeding the nitrite-containing stream continuously to the granular reactor in the anoxic phase. With a nitrogen and phosphorus removal efficiency of 81% and 94%, respectively, the system produces an effluent that is suitable for land irrigation from a wastewater stream containing 270 mg N/L of total nitrogen and 40 mg P/L of total phosphorus. © 2008 Elsevier Ltd. All rights reserved.
10.1016/j.watres.2008.04.012
Read more
High nitrous oxide production from thawing permafrost
Elberling, Bo et al. (2010),
Nature Geoscience,
vol. 3,
332-335
Elberling, Bo, Christiansen, Hanne H., Hansen, Birger U. (2010),
Nature Geoscience,
vol.
3,
332-335
Permafrost soils contain nearly twice as much carbon as the atmosphere. When these soils thaw, large quantities of carbon are lost, mainly in the form of methane and carbon dioxide. In contrast, thawing is thought to have little impact on nitrous oxide emissions, which remain minimal following the summer thaw. Here, we examined the impact of thawing on nitrous oxide production in permafrost cores collected from a heath site and a wetland site in Zackenberg, Greenland. Rates of nitrous oxide production in the heath soil were minimal, regardless of the hydrological conditions. Although rates of nitrous oxide production in the wetland soil were low following thawing, averaging 1.37 g N h 1 kg 1, they were 18 g N h 1 kg 1 for permafrost samples following thawing, drainage and rewetting with the original meltwater. We show that 31% of the nitrous oxide produced after thawing and rewetting a 10-cm permafrost coreequivalent to 34 mg N m 2 d 1 was released to the atmosphere; this is equivalent to daily nitrous oxide emissions from tropical forests on a mean annual basis. Measurements of nitrous oxide production in permafrost samples from five additional wetland sites in the high Arctic indicate that the rates of nitrous oxide production observed in the Zackenberg soils may be in the low range. © 2010 Macmillan Publishers Limited.
10.1038/ngeo803
Read more
Intermittent aeration to regulate microbial activities in membrane-aerated biofilm reactors: Energy-effic…
Ma, Yunjie et al. (2022),
Chemical Engineering Journal,
vol. 433,
133630
Ma, Yunjie, Piscedda, Andrea, Veras, Antia De La C., Domingo-Félez, Carlos, Smets, Barth F. (2022),
Chemical Engineering Journal,
vol.
433,
133630
Membrane-aerated biofilm reactors (MABR) are being applied for autotrophic nitrogen removal, yet control of nitrogen turnover remains challenging in MABR counter-diffusion biofilms. In this study, we regulated microbial activities in two lab-scale MABRs by providing continuous versus intermittent aeration. Nitrogen consumption by different functional microbial groups was estimated from bulk measurements via a mass balance approach. Nitrite-oxidizing bacteria (NOB) proliferated under continuous aeration while they were significantly suppressed under intermittent aeration, and NOB suppression activated anaerobic ammonium oxidation. Nitritation performance in the MABR was studied through long-term bulk measurements and in situ biofilm microprofiles of dissolved oxygen (DO) and pH. During intermittent aeration pH effects rather than DO effects determined nitritation success, especially ammonia speciation, which serves as substrate and inhibitor in nitrification processes. Biofilm transition phases were monitored upon aeration switches. Canonical correspondence analysis suggested that the relative transition after anoxia and aeration intermittency were less decisive for biofilm performance than the relative aeration duration. Heterotrophic bacteria displayed minor denitrification rates with aeration control, but contributed to mitigation of nitrous oxide (N2O) emissions. N2O production hotspots were identified at the top of the anoxic biofilm zone under continuous aeration. Instead, under intermittent aeration an anoxic N2O reduction zone was established. Our observations support intermittent aeration control of MABRs as a simple strategy for energy-efficient nitrogen removal with low N2O emission.
10.1016/j.cej.2021.133630
Read more
The combined effect of short-term hydrological and N-fertilization manipulation of wetlands on CO2, CH4, …
Bonetti, Giuditta et al. (2022),
Environmental Pollution,
vol. 294,
118637
Bonetti, Giuditta, Limpert, Katy E., Brodersen, Kasper Elgetti, Trevathan-Tackett, Stacey M., Carnell, Paul E., Macreadie, Peter I. (2022),
Environmental Pollution,
vol.
294,
118637
Freshwater wetlands are natural sinks of carbon; yet, wetland conversion for agricultural uses can shift these carbon sinks into large sources of greenhouse gases. We know that the anthropogenic alteration of wetland hydrology and the broad use of N-fertilizers can modify biogeochemical cycling, however, the extent of their combined effect on greenhouse gases exchange still needs further research. Moreover, there has been recent interest in wetlands rehabilitation and preservation by improving natural water flow and by seeking alternative solutions to nutrient inputs. In a microcosm setting, we experimentally exposed soils to three inundation treatments (Inundated, Moist, Drained) and a nutrient treatment by adding high nitrogen load (300 kg ha−1) to simulate physical and chemical disturbances. After, we measured the depth microprofiles of N2O and O2 concentration and CO2 and CH4 emission rates to determine how hydrological alteration and nitrogen input affect carbon and nitrogen cycling processes in inland wetland soils. Compared to the Control soils, N-fertilizer increased CO2 emissions by 40% in Drained conditions and increased CH4 emissions in Inundated soils over 90%. N2O emissions from Moist and Inundated soils enriched with nitrogen increased by 17.4 and 18-fold, respectively. Overall, the combination of physical and chemical disturbances increased the Global Warming Potential (GWP) by 7.5-fold. The first response of hydrological rehabilitation, while typically valuable for CO2 emission reduction, amplified CH4 and N2O emissions when combined with high nitrogen inputs. Therefore, this research highlights the importance of evaluating the potential interactive effects of various disturbances on biogeochemical processes when devising rehabilitation plans to rehabilitate degraded wetlands.
10.1016/j.envpol.2021.118637
Read more
