Cyclobutane Detector – gas sensor Explosion proof, Zone 1, SIL 2, ATEX certified

Cyclobutane is highly flammable (with LEL as 1.80% v/v) liquid. Our Smart S series detector monitor LEL concentration of cyclobutanes gas in ambient air or in ducts. It is flameproof or explosion proof sensor transmitter with ATEX and safety integrity level SIL 2 certified for hazardous area Zone 1, 2 installation. It is ideal for installation in pesticides, pharmaceuticals, refinery, manufacturing units and so on

It is available with LCD Display, on-board relay contacts, flashing alarm LEDs, auto diagnostic watch dog, non-intrusive calibration, with industry standard linear analog output.


Cyclobutane gas LEL Monitor – flameproof sensor transmitter with ATEX, SIL 2 for hazardous area Zone 1, 2

online, continuous detection and monitoring of LEL or flammable level of Cyclobutane gas or vapour in ambient air or ducts, flameproof / explosion proof certified Zone 1, 2 – ATEX, SIL 2, with / without display, contact relays, flashing alarm LEDs, RS485 serial interface
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Model: S2XX7

Cyclobutane is a colourless gas and commercially available as a liquefied gas. Derivatives of cyclobutane are called cyclobutanes. Cyclobutanes are extremely flammable and can be easily ignited by heat, sparks or flames. It Will form explosive mixtures with air. Vapors from liquefied gas are initially heavier than air and spread along ground.

Flammable Limits: Lower (LEL): 1.80% v/v     Upper (UEL): 11.10% v/v.

SMART S series Cyclobutane gas or vapour sensor transmitter is high performance, rugged, industrial grade, flameproof or explosion proof instrument for LEL concentration detection. The instrument can be installed for flammability level or LEL detection of Cyclobutane gas or leakage in all industrial and commercial area eg. biotechnology, manufacturing, medicine and pharmaceuticals etc.

The detector can be installed at walls, surfaces or in ducts for monitoring in gas or air sample. It is ATEX EEx’d’ certified with SIL 2 safety integrity level for hazardous area installation Zone 1 and 2.
Explosion proof or flameproof gas sensor transmitter - ATEX, Zone 1, 2 for all toxic, flammable gas, oxygen
The sensor transmitter offers linear, proportional analog output in industry standard current signals, over measuring range of 0 ~ 100% LEL (lower explosive limit). The detector works on highly sensitive catalytic bead based pellistor sensor cell, with low response time. It has unique feature of auto diagnostic watch dog with zero-point tracking feature. Due to its 10-bit microprocessor based control unit, it offers high accuracy over long term. The detector is also equipped with sintered filter with flashback arrestor for enhanced safety.

Cyclobutane gas detector - analog LEL monitor, LCD Display for hazardous area Zone 1, aromatic solvents LEL
Cyclobutane gas detector – analog LEL monitor, LCD Display for hazardous area Zone 1, aromatic solvents LEL

It also offers optional features like inbuilt LCD display, flashing alarm LEDs, on-board potential free relay contacts (24VDC @ 1 A), RS485 serial interface with Modbus RTU communication.


Key Features:

  • Catalytic bead based Pellistor sensor cell with low flash energy
  • 10-bit microprocessor control unit
  • Non-intrusive one-man calibration via hall effect switches
  • ATEX certified explosion proof / flameproof, suitable for Zone 1, 2 gas explosion installation
  • Linear, proportional analog industry standard current output
  • Continuous system self-diagnosis with watch dog
  • Flashback arrestor with sintered filter
  • Auto Zero-point tracking to zero-point compensation
  • SIL 2 HW TUV certified
  • RS485 serial interface with Modbus RTU communication (optional)
  • 1 or 3 relay output module (optional)
  • System and alarm LED indicators (optional)
  • Modbus RTU communication over RS485 serial interface


Cyclobutane gas detector for LEL monitoring in flameproof Zone 1, 2 area, ATEX, SIL 2 certified
Cyclobutane gas detector for LEL monitoring in flameproof Zone 1, 2 area, ATEX, SIL 2 certified

Technical Specifications:

  • Measuring Parameters: LEL or flammable concentration of Cyclobutane gas (1.80% v/v)
  • Sensor Technology: Catalytic bead based pellistor sensor cell
  • Measuring range: 0 ~ 100% LEL
  • Response time (t90): < 30 sec
  • Control unit: 10-bit microprocessor based
  • Warm up time: < 5 mins
  • Auto zero-point tracking for drift compensation
  • Power supply: 24V DC
  • Ingress protection: IP65
  • Enclosure: Stainless steel (for sensor cell), anti-static epoxy coated metal alloy (for transmitter)
  • Output: linear, proportional 4-20mA
  • Mounting: wall, duct, pipeline
  • Safety integrity level: SIL 2
  • ATEX marking:
    • CE 722 Ex II 2G EEx d IIC T6
    • CE 722 Ex II 3G EEx nA IIC T6
  • Optional: LCD Display, alarm LEDs, potential free relay contacts
  • Hazardous area: Zone 1, 2



  • Biotechnology and biology
  • Pharmaceuticals, medicinal formulations
  • Biochemistry
  • Manufacturing plants