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H2S sensor

Hydrogen sulfide

Reliable real-time
information on H2S

SENSOR-BASED | BEST AVAILABLE ACCURACY

Hydrogen-sulfide
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Where is it found?

Most of this gas in the atmosphere has a natural origin from organic matter decomposition. Anthropically, it occurs in processes involving sulphur compounds and organic matter at high temperatures.

Some industrial activities that emit this gas are paper pulp manufacturing, oil refining, water treatment plants and the viscose manufacturing textile industry.

Why is it harmful?

Hydrogen Sulfide (H2S) affects mainly the respiratory system with the first symptoms being nose, throat and eye irritation.

This compound begins to be detected by human smell at concentrations much lower than those that can harm health. Short-term exposures to high concentrations can cause headaches, dizziness and vomiting.

The H2S cartridge has a built-in electrochemical sensor very sensitive to its target pollutant allowing it to detect small changes in H2S concentration. This cartridge also responds to methyl mercaptan (CH4S) and other total reduced sulphur compounds (TRS).

To cover different applications, there are 2 measurement ranges:

  • Type A: detects low ppb concentrations in real environments. Although the Kunak algorithm corrects the temperature variations well, it is not recommended to use this cartridge to measure levels below 15 ppb.
  • Type B: a higher range version that can measure up to 20 ppm, not so precise at low concentrations.

Technical specifications

Type
Electrochemical
Unit of measurement
µg/m3, ppb(A)
mg/m3, ppm(B)
Measurement range(1)
0 - 2,000 ppb(A)
0 - 20 ppm(B)
Resolution(2)
1 ppb(A)
0.01 ppm(B)
Operating temperature range(3)
-30 to 50 ºC
Operating RH range(4)
0 to 99 %RH
Recommended RH range(4)
15 to 90 %RH
Operating life(5)
> 24 months
Guarantee range(6)
100 ppm
Limit of Detection (LOD)(7)
2 ppb(A)
0.01 ppm(B)
Repeatability(8)
4 ppb(A)
0.01 ppm(B)
Response time(9)
< 60 sec
Typical accuracy(11) (12)
± 10 ppb(A)
± 0.05 ppm(B)
Typical precision R2 (10)
> 0.8
Typical slope(10)
0.78 - 1.29
Typical intercept (a)(10)
-5 ppb ≤ a ≤ +5 ppb(A)
-0.05 ppm ≤ a ≤ +0.05 ppm(B)
DQO - Typical U(exp)(13)
-
Typical Intra-model variability(14)
< 2 ppb(A)
< 0.02 ppm(B)
  1. Measurement range: concentration range measured by the sensor.
  2. Resolution: the smallest unit of measurement that can be indicated by the sensor.
  3. Operating temperature range: temperature interval at which the sensor is rated to operate safely and provide measurements.
  4. Operating RH range (Recommended RH range): humidity interval at which the sensor is rated to operate safely and provide measurements.
  5. Operating life: lifetime of the sensor at normal conditions.
  6. Guarantee range: limit covered by the guarantee.
  7. LOD (Limit Of Detection): measured at laboratory conditions at 20ºC and 50% RH. The limit of detection is the minimum concentration that can be detected as significantly different at zero gas concentration, based on the metric from the Technical Specification CEN/TS 17660-1:2022.
  8. Repeatability (measured at laboratory conditions at 20ºC and 50% RH): closeness of the agreement between the results of successive measurements of the same measure carried out under the same conditions of measurement, based on the metric from the Technical Specification CEN/TS 17660-1:2022.
  9. Response time: time needed by the sensor to reach 90% of the final stable value.
  10. Statistical metric: statistics obtained between the device hourly measurements and reference instruments for 1 to 8 months field test between -10 to +30ºC in different countries. (*) The expected error for PM10 is higher in the presence of coarse particles.
  11. Mean Absolute Error: it is the average mean absolute error (MAE) obtained between the device hourly measurements and reference instruments for 1 to 8 months of field test between -10 to +30ºC in different countries.
  12. Error: it is the error of the sensor at reading measurement or full scale.
  13. DQO-Typical U(exp): Data Quality Objective expressed as the Expanded Uncertainty in the Limit Value obtained between hourly measurements of the device and the reference instruments for 1 to 8 months field test between -10 to +30ºC in different countries, based on the metric from the European Air Quality Directive 2008/50/EC and from the Technical Specification CEN/TS 17660-1:2022. (*) The expected error for PM10 is higher in the presence of coarse particles.
  14. Typical intra-model variability: calculated as the standard deviation of the three sensor means in 1 to 8 months field test between -10 to +30ºC in different countries.

It is essential to have an instrument that is capable of accurately measuring pollution levels and providing reliable results to make informed decisions on air quality and public health.

Javier Fernández

CEO & Co-founder - Kunak