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Hydrogen Sulfide (H2S) Gas Sense Toxic Gas Detector

This product is currently out of stock and unavailable.

SKU: ZS-H2S/100 Category: Brand:


Hydrogen sulfide is a colourless gas with a strong distinctive smell liken to rotten eggs. Hydrogen sulfide can naturally be produced as a byproduct of decomposition (for instance by swamps and sewers) and is highlty toxic, corrosive, flammable and explosive.

The Gas Sense HS2 detector has an electrochemical sensor available in target rages of 0-100, 0-200 or 0-500ppm. 3 output relays are avaible which trigger at a pre-alarm, alarm level 1 and alarm level 2 and these values can be configured within certain limits (see Specification tab).


Standalone Mode

In stand alone mode, the detector has 3 relay outputs, and a monitored 24V output (Intended for alarm sirens). The 3 relay outputs correspond to the 3 alarm levels of PREALARM, ALARM 1 and ALARM 2. Each of these threshold levels has a default setting, and can be altered by +/- 5% or +/- 10%.

The detector will display the gas type, the current status (normal, fault or alarm), along with the current sensor reading on its 2 x 16 character LCD display. As the gas concentration level rises, the detector will light its relevant alarm LEDs and operate its relays. They operate concurrently, so that in the highest alarm level, all lower alarm LEDs & relays will remain ON.

System Mode

In System mode, the detector will display SYS to indicate that it is now part of a system. It will function similar to when it is in Stand alone mode, except the alarm relays will be under the control of the fire panel. This feature allows the control panel to monitor the system as a whole before deciding whether or not to operate an output.

The detectors can also be locally recalibrated, with menu options to set the zero level, and options to set the calibration span, with the use of a calibration gas cylinder filled with the full scale gas concentration level.

At the end of the recommended working life of the sensor, a replacement sensor should be fitted. The part numbers for each sensor are shown on the specification table.


Hydrogen sulfide is slightly heavier than air so the detector should be installed 30cm to 50cm from the floor. Typical coverage is 50m² however this is subject on the the airflow conditions in the area to be protected.

If the gas detector is being installed to monitor a specific risk, then the detector should be located approximately 1.5m away from that point (this is because if the gas escapes under pressure, it may be forced past the sensor, rather than into it, if the detector is too close).

Like all gas detectors, the best place to install a Gas Sense detector will depend on the target gas.


  • Electrochemical Hydrogen Sulfide (H2S) sensor
  • Available in 0-100, 0-200 or 0-500ppm target ranges
  • 3 output relays activate at pre-alarm, alarm level 1 and alarm level 2
  • Can operate in standalone or system modes (multiple gas controller panel available)


  • Target Gas Range : 0-500ppm, 0-200ppm or 0-100ppm
  • Supply Voltage : 24V DC
  • Sensor Type : Electrochemical
  • Sensor Life : 2 years
  • Specific Gravity (Air=1) : 1.19
  • Pre Alarm (PPM) Bold = Default :
    • 0-500ppm Version : 050ppm, 075ppm, 100ppm, 125ppm, 150ppm
    • 0-200ppm Version : 020ppm, 030ppm, 040ppm, 050ppm, 060ppm
    • 0-100ppm Version : 010ppm, 015ppm, 020ppm, 025ppm, 030ppm
  • 1st Alarm (PPM) Bold = Default :
    • 0-500ppm Version : 100ppm, 125ppm, 150ppm, 175ppm, 200ppm
    • 0-200ppm Version : 040ppm, 050ppm, 060ppm, 070ppm, 080ppm
    • 0-100ppm Version : 020ppm, 025ppm, 030ppm, 035ppm, 040ppm
  • 2nd Alarm (PPM) Bold = Default :
    • 0-500ppm Version : 150ppm, 175ppm, 200ppm, 225ppm, 250ppm
    • 0-200ppm Version : 060ppm, 070ppm, 080ppm, 090ppm, 100ppm
    • 0-100ppm Version : 030ppm, 035ppm, 040ppm, 045ppm, 050ppm
  • Operating Temperature : -20°C to 50°C
  • Maximum Humidity (Constant) : 15-90% RH
  • Maximum Humidity (Intermittent) : 0-99% RH
  • IP Rating : IP65
  • Quiescent Current : 48mA
  • Response Time : 20 seconds
  • Storage Time Without Comprising Lifetime : 6 months
  • Recommended Storage Temperature : 0°C- 20°C



Additional information

Weight 2 kg
Detection Type