Catalytic Bead Gas Sensor Module 5100-02-IT

Sierra Monitor’s 5100-02-IT module monitors combustible gases such as Methane, Hydrogen, Propane, and others.

The 5100-02-IT module is based on catalytic bead technology, a consistent and reliable method of detection that offers excellent response times to the target gases.

As the longest rated and FM-approved calibration cycle for any catalytic bead gas sensor, the 5100-02-IT module has minimal maintenance requirements and only requires six month calibration intervals. Although the 5100-02-IT module can be used as a stand-alone sensor, it can also be used as a 4-20 mA component or as a Modbus RTU node. For higher level system capability, the module can interface directly to Sierra Monitor’s Sentry IT Controller to enable system level Modbus serial communications, area and zone alarm management, extensive system diagnostic features, WebServer interface, and multiplexing sensor connections.

The Catalytic Bead Combustible Gas Sensor Module 5100-02-IT is approved and certified by a variety of third party agencies, including UL, FM, ATEX, SIL, ABS, CSA, and CE. These approvals and certifications assure our customers that we carry only the highest quality of products.

Catalytic Bead Gas Sensor Module 5100-02-IT

  • Integral LED Display – Easily calibrate and access gas concentrations, relay statuses, and diagnostics
  • Menu-Driven System – Rapidly adjust user-friendly configuration of alarm setpoints, calibration, maintenance, and alarm acknowledgment
  • 6 Month Calibration Interval – Dramatically reduce maintenance for the user
  • Non-Intrusive Calibration – Calibrate the module without declassifying the area
  • Internal Continuous Self-Diagnostics – Automatically indicate any fault or optics problems
  • Optically Isolated 4-20 mA Output – Interface effortlessly with common factory communication links and provide flexibility for the output
  • Modbus RTU Interface –Provide an easy interface to the world’s most common industrial protocol interface
  • SMC Sentry Digital Bus Interface – Connect easily with existing Sentry systems that have been in operation for many years
  • Optional Remote Sensor Configuration – Access the controller over a remote network for convenience or for hard-to-access areas
  • HART Interface – Effortlessly communicate over legacy 4-20 mA analog instrumentation wiring

Specifications for Catalytic Bead Gas Sensor Module 5100-02-IT

Sensor Type

  • Catalytic Bead (Pellistor)


  • Range
    • Repeatability: +/- 1% LEL
    • Response Time: T60 < 10 sec
    • Calibration Frequency: 180 days
    • Accuracy:
      • +/- 1% for 0-50% LEL range
      • +/- 2% for 51-100% LEL range


  • Display: Fixed and scrolling LED
  • Signal Output:
    • Sentry digital bus
    • Analog 4-20 mA
      • 3-wire Non-Isolated
      • 4-wire Isolated
    • Serial RS-485 Modbus RTU
  • Relay: Optional


  • Relays:
    • Optional: 3 Relays (Warning, Alarm, Trouble)
  • HART 7 Capable
  • Remote Sensor: Up to 50 feet (15.2 m)


  • Power consumption: 3 watts max
  • Input voltage: 24 VDC nominal: 10-30 VDC
  • RFI/EMI Protection: EN50081-2, EN50082-2

Operating Range

  • Ambient Temperature Range: -40 oF to 176oF (-40oC to 80oC)
  • Relative Humidity: 0-99% Non-Condensing


  • Dimensions (H x W x D)
    • A1 & A2: 6.9 x 5.7 x 3.9 in. (17.5 x 14.5 x 9.9 cm)
    • S1 & S2: 7.5 x 5.0 x 4.4 in. (19 x 13 x 11 cm)
  • Weight
    • A1 & A2: 3.4 lb. (1.5 kg)
    • S1 & S2: 7.2 lb. (3.3 kg)
  • Housing: Epoxy coated Aluminum or 316 Stainless Steel
  • Hazardous Area Classification:
    • Explosion proof, Class 1, Div. 1, Groups B, C, D Class 1, Zone 1, Group IIC, IP66, IP 65, NEMA 4X II2 GD, Ex d IIC T6 = -40 oC to 85oC
  • Warranty: 2 years


  • UL 2075: ETL Approved
  • FM Approval 6320: Combustible Gas Detector Performance
  • FM Approval 3600: Class I Div. 1, Groups B, C, D
  • ATEX Certified: II 2G, Ex d IIB + H2 T5 Gb
  • IECEx Certified: Ex d IIB + H2 T5 GB
  • CSA Approval: For enclosure in hazardous locations
  • CCCF: Certificate for China
  • CQST: Certificate for China
  • SIL-2 Certified: Certified by Lloyd’s Register (IEC 61508)
  • CE Marked: Certificate of Approval
  • ABS: Certificate of Compliance
  • CCOE/PESO: Certificate for India
  • PDO Approval: Petroleum Development Oman Certificate of Registration
  • ISO 9001:2008: Registered Quality System