• Detection of combustible, toxic Gases and Oxygen
  • Non-intrusive calibration
  • Smart sensors
  • Programmable relays
  • 2-wire, 3-wire, ModBus
  • Flame proof Junction Box
  • Available in stainless steel
  • Available in wireless version
  • Flame proof Junction Box Approval CCOE & CMRI


The ATS-109TD Sensor/Transmitter operates on 24 VDC power and features LED alarm  indicators, 4-20 mA output and optional alarm relay board. This sensor/transmitter can be connected to various applied controllers or computer-based instrumentation, such as PLC or similar instrumentation.

Combustible gas Sensor/Transmitter 0-100%LEL

The Model ATS-109TD incorporates a pellistor or catalytic bead sensor. This sensor consists of a matched pair of elements, one active and the other for compensation. When in contact with a combustible hydrocarbon or solvent causes the gas or vapor to "burn" or oxidize at concentrations below the Lower Explosive Limit (LEL). This oxidization process raises the temperature of the active bead and increases the resistance of the internal wire coil. The second bead does not have the catalytic coating and provides compensation for environmental conditions including temperature and humidity. When these elements are connected to the circuit, a useable signal is produced that is proportional to the gas concentration.

Electrochemical Sensor/Transmitter for H2, O2, CO, H2S and other Toxic Gases

The ATS-109TD Series Sensor/Transmitters utilize electrochemical type cells to detect the target gas. These cells consist of electrodes, electrolyte and an air/liquid separation barrier. Gas molecules enter the cell and, as a result of an oxidation/reduction reaction, generate an electrical current proportional to the gas concentration.

NDIR Hydrocarbon Sensor/ Transmitter

The ATS-109TD incorporates a sensor that operates on the NDIR principle to monitor the concentration of hydrocarbon gas. It can be calibrated for a specific gas, such as methane, but it also responds to some other hydrocarbon gases, including propane, butane, etc. The sensor features an integral semiconductor for temperature compensation, a durable tungsten filament IR light source, filter and a dual temperature-compensated pyroelectric infrared detector.


  • Environmental Monitoring
  • Area Monitoring
  • Pulp & Paper
  • Leak Detection & Monitoring
  • Chemical Plants
  • Refineries/Petrochemical
  • Hazardous Area
  • Water/West water Treatment
  • Fire Services
  • Mines



Principle   :      Electrochemical, Solid State Semiconductor and Catalytic
Range   :      %V/V, % LEL, PPM, PPB
Resolution   :      0.1 Unit or 1 Unit (Application based)
Sampling Method   :      Diffusion
Display   :      Alphanumeric LED
Alarm   :      Relay Contact NO+NC
Anolog Out Put   :      4-20mA
Digital Out Put   :      RS 232, RS 485 and Modbus Comminication Protocol 
Power Source   :      24V DC or 230VAC
Accuracy   :      +/2%
Response Time   :      <5 Second
Sensor Life   :      2-3 Years