S2 Series Hydrogen (H2) specific 0 – 1,000 ppm sensor/transmitter with explosion proof j-box, CSA



S2 Series Explosion Proof 65-2443-1000-05

The RKI S2 series gas sensor/transmitters are highly reliable and very cost effective for the detection of common gas hazards. The S2 series are available for LEL, H2 Specific (LEL, and ppm), Oxygen, H2S, CO, and for a variety of toxic gases. The transmitters for LEL, H2 Specific, Oxygen, H2S, CO2, and Carbon Monoxide are explosion-proof with flame arrestors, and approved for use in hazardous areas (Class l, Groups B, C, D). An optional non-explosion proof version is available for oxygen, H2S, CO, and CO2 in Class 1 Div 2. LEL sensors are available using catalytic bead and infrared technologies.

The toxic sensors are electrochemical type plug-in sensors, which provide high specificity, fast response, and long life. The plug-in design allows quick replacement in the field with no tools required. Toxic sensors are designed for use in Class I, Div. 2 hazardous locations. Sensors available for NH3, SO2, PH3, AsH3, and HCN.

The S2 transmitters can be used either indoors or outdoors. The flame arrestors for the explosion-proof versions utilize a patented coating which make them water repellent. Splash guards are also available for use in very wet environments. An optional stainless steel junction box is available for corrosive environments.

All of the S2 transmitters are designed to interface with RKI controllers, or with PLC/DCS systems.

  • Available gases include LEL, H2S, CO, PPM H2, and CO2
  • Toxic gases include NH3, SO2, HCN, and more
  • Infrared sensor for combustibles and CO2
  • Hydrogen-Specific now available
  • Patented water repellent sensor coating
  • 4-20 mA output
  • Explosion proof construction
  • Optional stainless steel junction box
  • Petrochemical Plants
  • Refineries
  • Gas Plants
  • Offshore Drilling Platforms
  • Water & wastewater treatment plants
  • Pulp & paper mills
  • Gas, telephone, & electric utilities
  • Parking garages
  • Manufacturing facilities
  • Steel
  • Automotive
  • Chemical storage buildings
LEL (General Purpose)LEL (H2 Specific)H2 PPM (Hydrogen)O2 (Oxygen)H2S (Hydrogen Sulfide)CO (Carbon Monoxide)CH4 (Methane)HC (Hydrocarbons)CO2 (Carbon Dioxide)
Part #65-2405RK65-2451RK65-2443-50065-2322RK65-2331RK65-2336RK65-2394RK-CH465-2394RK-HC65-2396RK-02
SensorCatalyticMetal oxide semiconductorGalvanic cellElectrochemicalInfrared
Measuring Range0-100% LEL0-100% LEL (H2 Specific)0-500 ppm0-25% Vol.0-100 ppm0-300 ppm0-100% LEL0 - 5000 ppm
0-1000 ppm0 - 5% Vol.
0-2000 ppm0 - 50% Vol.
0 - 100% Vol.
Lower Detectable Limit (LDL)2% of full scale0.1% Vol.2% of full scale
Accuracy (whichever is greater)± 5% of reading or ± 2% LEL± 10% of full scale± 0.5% O2± 5% of reading
± 2 ppm H2S
± 5% of reading
± 5 ppm CO
± 5% of reading or ± 2% of full scale
Response Time (T-90)30 Seconds20 Seconds45 Seconds90 Seconds60 Seconds90 Seconds30 Seconds30 Seconds30 Seconds
Max Current Draw (24VDC)70 mA (power wires)25 mA max, 2 wires60 mA (power wires)
25 mA (signal wires) 3 wires25 mA (signal wires) 3 wires
Life Expectancy2 to 3 years with normal exposure to flammable gas3-5 years with normal service5 years plus with normal service2-3 years with normal service5 years plus with normal service
Operating Environment
LocationIndoor or outdoor. Explosion proof for Class I, Div. 1, Groups B, C, and D.
Temperature-40°F to 167°F-4°F to 104°F-4°F to 113°F-40°F to 104°F23°F to 104°F-40°F to 122°F
-40°C to 75°C-20°C to -40°C-20°C to 45°C-40°C to 40°C-5°C to 40°C-40°C to 50°C
Humidity0 - 99% RH, non condensing
Housing J BoxCast aluminum explosion proof, optional stainless steel J-box available
SensorStainless steel explosion proof
ZeroSets transmitter output to 4 mA with zero output from sensor
SpanSets transmitter output to proper level when span gas is applied
Output4 - 20 mA signal
Operating Voltage11 VDC to 30 VDC19 VDC to 30 VDC19-30 VDC (250 OHMS impedance max)11 VDC to 30 VDC
Approvals65-2405RK: UL65-2451RK: UL65-2443-500: ULCSA NRTLC UL US
65-2405RK-05: CSA65-2451RK-05: CSA65-2443-1000: UL
65-2443-2000: UL
65-2443-500-05: CSA
65-2443-1000-05: CSA
65-2443-2000-05: CSA
ControllersCompatible with the following controllers: Beacon 110, Beacon 200, Beacon 410A, and 800, also PLC and DCS systems
WarrantyOne year materials and workmanship
S2 Wiring Matrix
S2 TransmitterNumber of Wires to ControllerMaximum Distance to Controller
18 AWG wire16 AWG wire14 AWG wire
LEL / IR / CO232500 ft.5000 ft.8000 ft.
Oxygen22500 ft.5000 ft.8000 ft.
H2S22500 ft.5000 ft.8000 ft.
CO22500 ft.5000 ft.8000 ft.
Toxics22500 ft.5000 ft.8000 ft.