Special Ultra-low range Hydrogen Sulphide (H2S) Sensor


General Description:

The NAP-523 is an Electrochemical gas sensor with 3 electrodes for the detection of Hydrogen Sulphide (H2S).

The sensor has been specially designed to give a very high output signal, resulting a very low detection range of 0 to 0.5ppm, and a resolution (with high quality circuitry) of +/- 0.05ppm. The sensor is also insensitive to humidity changes and alcohol vapours, making it ideally suitable for measuring low levels of H2S on breath for health monitoring.

The Sensor can also be used in any application where very low Environmental levels of H2S need to be detected or monitored.



Detectable Gas:

Detection range:

Maximum overload:

Output current:

Zero Offset (20oC)


Output drift in air:

Sensitivity Output Drift:

Response time (90%):

Temp depend. in air:

Expected lifetime:

Temperature Range

Humidity Range

Hydrogen Sulphide

0 – 0.5 ppm

1 ppm

550 +/- 150 nA/ppm

+/- 0.1ppm equiv.

+/- 5%

< +/-1ppm/year

< 2% /month

< 60 seconds

<0.5ppm (-20 to-50°C)

>2 years

-20 to +50 oC

15 to 90% RH (NC)


  •        3-Electrode design for greater stability
  •        Compact, leak-proof enclosure
  •        Resistant to shocks and vibration
  •        Terminals may be soldered
  •        Linear output
  •        Highly specific to target gas
  •        Unaffected by humidity
  •        Unaffected by Alcohol vapours
  •        Very Low Long term drift