OLCT 200 Fixed Gas Detector

Reliable Detection of Combustible and Toxic Gases and O2.

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  • Overview
  • Features
  • Specifications
  • Applications
  • Support
The OLCT-200 covers basically all common gas gases plus VOCs. In addition, it supports ModBus as well as HART Communication protocols. It also can be installed as a wireless (battery powered) gas detector. 
Wireless communication is becoming increasingly popular in gas detection, and it is sometimes the only way to ensure safety in existing infrastructure or remote locations.
The infrared sensor provides detection of explosive gases in more severe environmental conditions, where the presence of poisons could harm the use of a catalytic cell.
OLDHAM also offers a variety of wireless solutions compatible with the OLCT 200, including wireless controllers and solar-powered field monitors as well as wireless repeaters and accessories.
Contact your local Air-Met Sales Representative for more information.
  • SIL-2 – Hardware assessed to be SIL-2 capable
  • Security mode allows for lockout of critical parameters
  • "Fault Supervision" circuitry
  • Programmable warm-up and cal delays to avoid false alarms
  • Explosion-proof
  • Intrinsically Safe
  • HART® (opt)
  • RS-485 ModBus (opt)
  • Stainless Steel Enclosure (opt)
  • Programmable Relays (opt)
  • 2-wire, 3-wire Installations
  • Wireless Communication (opt)
  • Cold Climate Heater (opt)
  • Dual Gas Sensing (opt)
  • Remote Sensing (opt)
  • Large Sensor Offering—Electrochemical, Catalytic, Infrared, and Photo Ionisation Detection Sensors
Easy to Use
  • Smart Sensors
  • Large Graphical Display
  • 30min Trending
  • Backlit LCD (excluding 2-wire)
  • Non-Intrusive Calibration
  • Split Screen Display (dual sensor option)
  • Visual Alarm LEDs
  • Wireless communication is becoming increasingly popular in gas detection, and it is sometimes the only way to ensure safety in existing infrastructure or remote locations. The OLCT 200 wireless option offers many benefits to meet your application needs.
  • 900MHz or 2.4GHz FHSS
  • 10mW – 1W Adjustable Tx Power
  • CSA Div 1 and Div 2 Antennas
  • 256-bit Encryption
  • Indoor Range up to 3000' (900 meters)
  • Outdoor Range up to 10 miles (16 km)
  • High Receiver Sensitivity
  • Battery & Solar Powered Options
Combustible Gases: Catalytic, Infrared
Toxic / Oxygen: Electrochemical, PID
Enclosure: Epoxy Coated Aluminum or 316 Stainless Steel
Sensor: 316 Stainless Steel
Display Backlit LCD (2-Wire models do not have backlight)
Input Voltage
10 - 30 VDC
Lithium-Ion Battery (select wireless models)
Power Consumption
25mA @ 24VDC (EC Sensor)
100mA @ 24VDC (Cat, IR, PID Sensors)
+120mA @ 24VDC (for added energized relays)
+20mA @ 24VDC (for added RS-485 ModBus)
+210mA @ 24VDC (for added Arctic Heaters)
Ingress Protection NEMA 7X, IP66
Cable 2-wire, 3-wire, or 4-wire, shielded
Max. Cable Loop Resistance
500Ω @ 24VDC (2-wire configs)
750Ω @ 24VDC (3-wire configs)
Output Signal
Standard: 4-20mA (analog), 2-wire (sink), 3-wire (source)
Optional 1: Dual Isolated 4-20mA (source)
Optional 2: RS-485 ModBus (9600 Baud)
Optional 3: Wireless (900MHz or 2.4 GHz)
Optional 4: HART® Protocol
Alarm Relays (opt)
3 Relays (2 User Programmable, 1 Fault)
Form C (SPDT)
5 AMP @ 30VDC or 240 VAC "RESISTIVE"
Relays 1&2 are configurable for low and high alarms, normally energized or normally de-energised, and latching or non-latching
Fault Relay is always normally energised
Wireless (opt)
900MHz or 2.4GHz FHSS(Frequency Hopping Spread Spectrum)
256-bit AES Encryption (meets FIPS-197)
10mW - 1W Adjustable Transit Power (900Mhz only)
Div 1 XP and Div 2 Configurable
Consult factory for current approval status
CSA - Class 1, Div. 1, 2 - Groups A, B, C, D (2-wire config.) - Groups B, C, D (3-wire config.)
IS barrier required for intrinsically safe installations!
SIL-2 - hardware SIL-2 capable per EN 61508 (exida)
Dimensions 5.0" (127mm) W x 7.8" (197mm) H x 5.1" (130mm) D Shipping Weight Appox. 7 Lb (3.2 kg)
Operating Temperature -40°C to 60°C - (sensor specific)


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