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GT814 Toxic Gas Detector

Product Literature

  • Intelligent Model
  • Electrochemical Sensor
  • LCD Display
  • 4-20 mA ouput
  • Relay Contacts
  • 2 Alarm Set Points
  • Explosion-proof
  • Aluminum or Stainless Steel Controller Housing
  • Stainless Steel Sensor Housing

Keywords:  Toxic Gas Detector, Toxic Gas Monitor, H2S Detector, Hydrogen Sulfide Detector, NH3 Detector, Ammonia Detector, Chlorine Detector, Carbon Monoxide Detector

Features and Benefits

  • Intelligent toxic gas detector
  • Electrochemical cell provides increased accuracy, stability, reliability, and fast response
  • 4-20 mA output
  • User programmable LOW alarm and HIGH alarm setpoints
  • Voltage-free relay contacts for local control
  • Explosion-proof electronics housing Class I, Group A, B, C, D
  • Stainless steel sensor housing
  • Available up to IP66 rating
  • Magnetic switch initiates test or calibration sequence
  • Built-in automatic sensor replacement/maintenance and calibration reminder
  • Step-by-step on-screen calibration instructions for ease of use and maintenance
  • Shipped fully assembled and pre-calibrated
  • Available with wireless transmitter as an accessory with text, e-mail notifications feature
  • Available accessories include rain/waterspray shield, dust cover, duct mount, gas collection cone, and calibration kit
  • 5 Year Warranty
  • Made in USA


Product Summary

GT814 NOVA-Sensor Elite™ Toxic Gas Sensor is our latest intelligent model toxic gas detector which monitors the presence of toxic gases such as H2S or hydrogen sulfide, ammonia, carbon monoxide, chlorine, and other toxic gases.  Self-contained device, measures and displays the concentration of gas accumulated in a protected area, performs local control functions, and optionally transmits this information to a central control point.  Features a bright LCD display of gas, 4-20 mA output signal, dry contact relays, and on-screen calibration instructions.  5 Year Warranty.  Made in the USA.


  • Hydrogen Sulfide (H2S)
  • Ammonia (NH3)
  • Carbon Monoxide (CO)
  • Chlorine (CL2)
  • Ethylene Oxide (ETO) (C2H4O)
  • Hydrogen (H2)
  • Hydrogen Chloride (HCL)
  • Hydrogen Cyanide (HCN)
  • Hydrogen Peroxide (H2O2)
  • Nitric Oxide (NO)
  • Nitrogen Dioxide (NO2)
  • Phospine (PH3)
  • Sulfur Dioxide (SO2)


Use the NOVA-Sensor Toxic Gas Detector to alert personnel when life-threatening gas is present in a protected area. This detector uses an electrochemical fuel cell sensing element, and provides accurate measurements in all atmospheres. A high reserve of electrochemical activity insures a long life and excellent temperature stability. The performance is relatively unaffected by humidity, providing that conditions are noncondensing,

The display screen on the NOVA-Sensor continuously displays operating status and the actual concentration of toxic gas in parts per million (PPM). This reading is converted to a standard 4-20 mA signal, which may be connected to any remote device for remote display or logging. Relay contacts are provided which transfer when the gas SAFETY SYSTEMS TECHNOLOGY novagas toxic concentration exceeds the LOW ALARM and HIGH ALARM set points. Typical set points are adjusted by the installer upon installation and may be reset later by authorized personnel. The relays are suitable for controlling local HVAC equipment, alarm signal devices or for equipment shutdown. Fault relay contacts are also available which operate upon loss of power or internal failure of the unit.

The automatic calibration sequence is initiated by depressing the pushbutton switch located on the side of the enclosure. During calibration, step-by-step instructions are displayed on the NOVA-Sensor screen. There are no screwdriver or other manual adjustments required, and the calibration can be performed even in the presence of toxic gases.


Technical Specifications and Ordering Information

Technical Specifications

Sensor Type: Electrochemical cell
Modes: Normal operation, set-points, calibration, set-up
Warranty: 5 Years; 1 Year for cell
Approvals: Explosion-proof approved housing
Class I, Division I, Groups A, B, C, D;
Class I, Zone I, AEx d IIC; Type 4X
ATEX:  II 2G Ex d IIC Gb
Electrical Specifications
Input Power: 24 VDC nominal, 16 to 32 VDC
Relay Contact Ratings: 6 amps @ 28 VDC or 300 VAC resistive
1/8 HP @ 120/240 VAC
Analog Signal: 0-20 mA (600 Ohms or less)
0 mA  Malfunction
4 mA  Setup Mode/Calibrate
4 mA  Zero Reading
4 – 20 mA  0-XXX PPM
> 20 mA  Over-range
Display: Graphic Liquid Crystal Display
Displays target gas concentration in PPM;
Flashing screen in alarm mode;
Low brightness setting in power save mode
Field Connections: 4-20 mA output – three-wire shielded cable
All other connections:  22 AWG (.35mm²) to 12 AWG (4.0mm²)
Wireless Communication: Available with optional wireless transmitter with text, e-mail notification features
 Environmental Specifications
 Operating Temperature:  Electronics:  -40°F to 185°F (-40°C to 85°C)
 Storage Temperature:  Sensors:  32°F to 68°F (0°C to 20°C)
 Pressure Range:  Atmospheric ±20%
 Operating Humidity:  0-100% RH, non-condensing
 Ingress Protection:  IP40 to IP66
 Mechanical Specifications
 Dimensions:  14.44×5.75×4.375 inches
(159x146x111 mm)
 Weight: 10.0 lbs (4.5kg) Aluminum housing
16.0 lbs (7.2 kg) Stainless steel housing
Controller Housing:  Aluminum or Stainless Steel
 Sensor Housing:  Stainless Steel
 Specifications subject to change without notice. 

Ordering Information

Part No. Description
814-AL Model GT814 Toxic Gas Detector
Electronics in aluminum housing
     Sensor in stainless steel housing
814-SS Model GT814 Toxic Gas Detector
Electronics in stainless housing
     Sensor in stainless steel housing
 851-1  Rain shield, stainless steel (IP65)
 851-5  Water spray shield
(For IP66, requires 852-1-4)
 851-1  Dust cover, stainless steel
(Requires 851-5-4)
 854-1  Duct mount, stainless steel
 859-1  Gas sensor collection cone, stainless steel
 850-4  Sensor remote junction box
 857  Calibration kit (test gas sold separately)
 10121  Spare calibration/test key