SI-100C is a IEC Ex explosion proof gas sensor ready to installed hazardous and non-hazardous areas to prevent gas hazards caused oxygen depletion, toxic gas or combustible gas. Available to detect over 25 different gas types, see Ordering Information for details.

IECEx Approved

  • International Certified Explosive proof structure, Complent with all Australian Standards.
  • IP65: Water and dust resistant structure
  • 4-20mA Analog outputs
  • Built-in easy to use calibration mode
  • Easily replaceable sensor head.
  • Australian Certificate of Calibration


Locally Technically Supported by Gas Detection Australia.

Related Products

Generator Rooms

A range of devices from single point go / no go detectors such as the DA-2010 through to sophisticated IEC Ex type gas detectors / gas sensors can be used for detection of Natural gas, Propane, Butane and various other mixtures.

Designed, Manufactured and Supported in Australia.

Laboratory and Classroom Monitoring

When gas is piped into rooms for experimental purposes such as CO2, CO, or Natural Gas .The Gas Detection Australia range of sensors can be used to detect any leaks that may present a danger to health or explosion.

Designed, Manufactured and Supported in Australia.

Sewage Treatment Plant Monitoring

The presence of Hydrogen Sulphide  can be detected by using the Gas Detection Australia GDA 2529 gas sensor to detect leaks of Hydrogen Sulphide  and evoke deodorisation plant. The SI-100C gas sensor can be used to monitor for leaks of LEL levels of methane gas. In digester applications Carbon dioxide can be detected using the GDA 4350  

Designed, Manufactured and Supported in Australia.

Battery Room Monitoring

The SI-100C and a range of associated Gas Detection Australia controllers can be used in battery room gas detection  to detect hydrogen in battery rooms and sound alarms. The battery room gas detection systems comprise of a hydrogen gas sensor SI-100C and a gas sensor control unit. The Gas Detection Australia control unit  GDA 4020 or GDA 4011 is situated external to the battery room to display the gas concentrations and the alarm status. The battery room gas detection system can then be interfaced to extraction fans, sounders or other apparatus. For smaller battery charging rooms the standalone GDA 40126 can provide an integrated sensor and controller with outputs to drive extraction fans and sounders.

Designed, Manufactured and Supported in Australia.

Hazardous Areas (IEC Ex Certified)

IEC Ex approved gas detectors and sensors for use in Zone 1 and Zone 2 areas within Australia for both Toxic and Flammable gases.

Hazardous Areas are areas in which an explosive gas atmosphere is or may be expected to be present, in quantities such as to require special precautions for the construction installation and use of equipment construction, installation and use of equipment. Hazardous areas are classified into 3 zones based upon the frequency of the occurrence and duration of an explosive gas atmosphere, as follows:

  • Zone 0 - Area in which an explosive gas atmosphere is present continuously or for long periods or frequently.
  • Zone 1 - Area in which an explosive gas atmosphere is in which an explosive gas atmosphere is likely to occur in normal likely to occur in normal operation occasionally.
  • Zone 2 - Area in which an explosive gas atmosphere is not likely to occur in normal operation but, if it does occur, will persist will persist for a short period for a short period only.
  • Non hazardous area (safe area) - A non hazardous area is an area in which an explosive atmosphere is not expected to be present.

As per IEC60079-10-1 and AS/NZS 60079.29.2:2016

Specification NameSpecification Value
Detectable GasesSee Ordering Information for the full list of gas types and specifications
Accuracy of Reading±3% / Full scale
Parameter controlSwitch (calibration)
Power Requirements7V to 40V INPUT DC (24V DC 60mA normal)
Operating Current12V or 24V DC 60mA
Output Types4-20mA DC
Connection3 way plug connector
WiringSignal cable: 3-wire > 1.5sq(AWG16) / 2,500m max
Conduit connectionNPT 3/4" (2way)
Operating Temperature-20℃ ~ 55℃
Operating Humidity5% to 95% RH(Non-condensing)
Enclosure MaterialAluminium, Stainless steel(STS304)
Dimensions102(W) × 137(H) × 87(D)mm
Weight1.0 kg
Enclosure RatingIP65
ApprovalEx d IIC T5 (IEC Ex), ATEX, CNEx, INMETRO
Warranty24 months from date of dispatch
Calibration RequirementEvery year with 6 monthly functional tests if sensor operated at SATP

 SENKO SI-100C Explosion Proof Gas Sensor

  • SI-100C Explosion Proof Gas Sensor
  • User Manual
  • Calibration Certificate
Part Number Gas Sensor Technology Range Resolution Sensor life time
SI-100C-001 Oxygen (O₂) Electrochemical 0-30% Vol 0.1% Vol > 18 Months
SI-100C-002 Carbon Monoxide (CO) Electrochemical 0-500 ppm 1 ppm > 2 Years
SI-100C-003 Sulfur Dioxide (SO₂) Electrochemical 0-20 ppm 0.1 ppm > 2 Years
SI-100C-004 Hydrogen (H₂) Catalytic 0-100% LEL 1% LEL > 5 Years
SI-100C-005 Hydrogen (H₂) Electrochemical 0-1000 ppm Within 5 ppm > 2 Years
SI-100C-006 Hydrogen Sulfide (H₂S) Electrochemical 0-100 ppm 1 ppm > 2 Years
SI-100C-007 Hydrogen Sulfide (H₂S) PID 0-50 ppm 0.1 ppm > 6 Months
SI-100C-008 Hydrogen Peroxide (H₂O₂) Electrochemical 0~10ppm 0.1ppm > 2 Years
SI-100C-009 Combustible Catalytic 0-100% LEL 1% LEL > 5 Years
SI-100C-010 Combustible IR 0-100% LEL 1% LEL > 2 Years
SI-100C-011 Ammonia (NH₃) Electrochemical 0-100 ppm 1 ppm > 2 Years
SI-100C-012 Acetylene (C₂H₂) Catalytic 0-100% LEL 1% LEL > 5 Years
SI-100C-013 Ethanol (C6H5OH) Catalytic 0-100% LEL 1% LEL > 5 Years
SI-100C-014 Ethylene (C₂H4) Catalytic 0~100%LEL 1% LEL > 5 Years
SI-100C-015 Ethylene Oxide (C2H4O) IR 0-100% LEL 1% LEL > 2 Years
SI-100C-016 Ethylene Oxide (C2H4O) Electrochemical 0~30 ppm 0.1 ppm > 2 Years
SI-100C-017 Toluene (C6H5CH3) IR 0-100% LEL 1% LEL > 2 Years
SI-100C-018 Toluene (C6H5CH3) Catalytic 0-100% LEL 1% LEL > 5 Years
SI-100C-019 Acetic Acid (CH3COOH) Catalytic 0-100% LEL 1% LEL > 5 Years
SI-100C-020 Methane (CH4) IR 0-9999 ppm Within 20 ppm > 2 years
SI-100C-021 Methane (CH4) IR 0-100% LEL 1% LEL > 2 years
SI-100C-022 Methane (CH4) IR 0-100% Vol 1% Vol > 2 years
SI-100C-023 Methanol (CH3OH) Catalytic 0-100% LEL 1% LEL > 5 Years
SI-100C-024 Chlorine (CI₂) Electrochemical 0-5 ppm 0.1 ppm > 2 Years
SI-100C-025 Chlorine (CI₂) Electrochemical 0-20 ppm 0.1 ppm > 2 Years
SI-100C-026 Carbon Dioxide (CO₂) IR 0-2000 ppm Within 3 ppm > 2 Years
SI-100C-027 Carbon Dioxide (CO₂) IR 0-5000 ppm Within 3 ppm > 2 Years
SI-100C-028 Carbon Dioxide (CO₂) IR 0-5% Vol 0.1% Vol > 2 Years
SI-100C-029 Hydrogen Chloride (HCI) Electrochemical 0-10 ppm 0.1 ppm > 2 Years
SI-100C-030 Volatile Organic Compound (VOC) PID 0-1000 ppm Within 3 ppm > 6 Months
SI-100C-031 Xylene (C8H10) IR 0-100% LEL 1% LEL > 5 Years
SI-100C-032 Nitrogen Monoxide (NO) Electrochemical 0~100ppm 1ppm > 2 Years
SI-100C-033 Nitrogen Dioxide (NO₂) Electrochemical 0~20ppm 0.1ppm > 2 Years
Other gas types available on request



Part Number Image Description
SI-100C-### S SI-100C

SI-100C-### Replacement Sensor Head

SI-100 Filter   Replacement sintered metal filter
SI-100 Plug   PT 3/4
SI-100 Calibration Cap   Calibration Cap for SI-100 & SI-100C



  • Flammable Catalytic Sensor Models
    • Poisoning: some compounds will decompose on the catalyst and form a solid barrier over the catalyst surface. This action is cumulative and prolonged exposure will result in an irreversible decrease in sensitivity. The most common of these substances are: volatile lead or sulphur containing compounds; silicones; phosphates.
    • Inhibition: certain other compounds, especially hydrogen sulphide and halogenated hydrocarbons, are absorbed or form compounds that are absorbed by the catalyst. The resultant loss of sensitivity is temporary and in most cases a sensor will recover after a period of operation in clean air


  • Electrochemical Sensor Models
    • Poisoning: Senko sensors are designed to operate in a wide range of harsh environments and conditions. However, it is important that exposure to high concentrations of solvent vapours is avoided, both during storage and operation.


  • Oxygen Electrochemical Sensor Models
    • Poisoning:  Acid gases such as CO₂ and SO₂ will be absorbed by the electrolyte and tend to increase the flux of oxygen to the electrode. This gives an enhanced oxygen signal of approximately 0.3% of signal per 1% CO₂. Senko oxygen sensors are not suitable for continuous operation in concentrations of CO₂ above 25%.




CALGAS : Calibration Gas

To test and maintain accuracy gas detection systems require regular testing and calibration. GDA can provide you with a complete line of calibration equipment to calibrate all of our gas sensors and detectors. Our calibration gas cylinders all come with N.I.S.T. certification and ISO 17025 approval so you can be confident that you will receive gas with the highest accuracy levels.