Posted in | Gas Sensors

ARA H2S Single Gas Detector: Hydrogen Sulfide (H2S) Gas Detector

Industrial sites in the Petrochemical, Oil and Gas and Offshore sectors can turn into hazardous places if appropriate safety measures are not followed. ATEX-certified, reliable gas detectors are the key to ensuring the safety of workers.

High concentrations of hydrogen sulfide (H2S) can render the human body unconscious by desensitizing it in no time. Thus, reliable personal monitoring equipment is vital.

ARA H2S Single Gas Detector: Hydrogen Sulfide (H2S) Gas Detector.

Image Credit: Ion Science

The ARA H2S portable alarm from Ion Science is an economical, wearable clip monitor that can detect hazardous levels of H2S. The detector alerts workers if gas concentrations go beyond preset safety levels.

The ARA H2S clip monitor continuously runs maintenance-free for 24 months. The 36-month model offers much more service life for a competitively low cost. Its service life can be extended by simply placing the detector in hibernation mode when it is not used, mainly for consultants or contractors who visit the site occasionally.

The H2S sensor has been engineered to endure the most severe industrial working conditions, with the following typical applications:

  • Plant turnaround processes
  • Site-wide safety


The ARA Hydrogen Sulfide (H2S) unit has been designed by taking all the real-world applications into consideration. Each unit weighs about 92 g and is fitted with a strong clip that can be fixed in close proximity to the breathing zone. Since it is only 87 mm long, it is apt for small working spaces such as pipe or tanker maintenance and does not obstruct worker movement.

The three-signal system comprising of an audible alarm, flashing light and vibration warn the users when the H2S exposure levels reach hazardous concentrations, making it very much safe for all environments.

ARA personal gas monitors from ION Science

Video Credit: Ion Science

The self-test feature in the ARA Hydrogen Sulfide gas detector ensures that the visual, audio and vibration alarms function well on a daily basis, thereby ensuring worker safety.

The 30 downloadable latest event logs and design settings available in the ARA IR link are:

  • User ID
  • Bump test intervals
  • Self-test intervals
  • Low/high alarms

Ultimate Performance

  • Live H2S recordings
  • Strong to endure extreme working environments
  • Event logging download
  • Non-stop operation for 24 months
  • Water and dust resistant

Ultimate Safety

  • Modifiable high/low alarms
  • Calibration and bump test prompts
  • Prompt alarms

Ultimate Flexibility

  • Live reading or lifetime remaining data display option
  • Hibernation feature to prolong the service life of the device up to 36 months
  • The lifetime leftover countdown helps to plan for upcoming projects and site closures

Technical Specifications

Source: ION Science

Specification Value
Sensor Type Single plug-in electrochemical cell
Detection Range H2S: 0 to 100 ppm
CO: 0 to 300 ppm
SO2: 0 to 50 ppm
O2: 0 to 25 %
Event Log Storage Last 30 events
Battery 3.6 Vdc, 1.65 Ah, lithium battery
Battery Life Standard models: 24 months of operations (2 mins alarms per day)
Hibernation models: 36 months of operation (2 mins per day and using sleep function)
User Options User ID
Low Alarm
High Alarm
Displayed Data (live reading or lifetime remaining)
Bump-Test Interval
Calibration Interval
Self-test Interval
Alarms Audio Alarm: (95 dB @ 10 cm)
Visual Alarm: LED
Vibrating Alarm: Vibrator (operates at ± 10 °C)
Temperature H2S, CO, SO2: – 40 to 60 °C
O2: – 30 to 60 °C
Humidity: 5 – 95 % RH
Ingress Protection IP67
Display Liquid Crystal Display (LCD)
Weight and Dimensions 92 g (3.2 oz)
87 x 50 x 29 mm (3.4 x 2.0 . 1.1 inch)


  • *All specifications mentioned are at calibration point and under the same ambient conditions.
  • Specifications are based on isobutylene calibration at 20 °C, 90% RH, and 1000 mBar
  • *Model dependent

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