Combustion analyzer: Ametek Thermox WDG-V

Prevention is so Easy… Living Through a Disaster Isn’t

Adobe PDF ReaderAmetek Thermox WDG-V Combustion Analyzer Sensor PDF

Ametek Thermox WDG-V Combustion Analyzer
Combustion analyzer: Ametek Thermox WDG-V

Why the need for a combustion analyzer? The reliable identification of low combustion oxygen in a fired heater or boiler has always been critical to the effectiveness of the Burner Management System for proper control and safety.

Low emission burners and aggressive firing control points to achieve increased efficiency and emission reductions have driven the industry to tighter control measures.  But tighter control measures also hold a greater potential for combustion events. Reducing the risk of a combustion event has become a priority and has led to the implementation of Safety Instrumented Systems (SIS).  This additional layer of safety is added to the Basic Process Control System.

The WDG-V combustion analyzer has been designed to provide an additional layer of safety with the measurement of excess O2, Combustibles and Methane and by using these measurements to ensure the safe operation of the Burner Management System.

Ametek Thermox WDG-V Combustion Analyzer HMI remote calibration
Combustion analyzer HMI: Amevision

Combustion analyzer Ametek Thermox WDG-V Features:

  • Precise control of low O2 setpoints with confidence
  • CO detection for control interlocks and safety shutdown
  • Predictive diagnostics
  • SIL 2 Capable for SIS implementation of IEC 16508/61511

Ametek Thermox WDG-V combustion analyzer

Principle of Operation (O2)

Zirconium oxide for net oxygen measurement and dual hot-wire catalytic detectors for both combustibles and methane.

Output Range (O2)

Oxygen: From 0-1 to 0-100%
Combustibles: 0-1000 PPM with Overrange 0-2,000 PPM to 0-10,000 PPM, 0-2 to 0-5%
Hydrocarbon: 0-5%

Accuracy (O2)

±0.75% of measured value or ±0.05%, whichever is greater
Combustibles: ±2% of full scale output range
Hydrocarbon: ±5% of full scale output range


Oxygen: 90% of a step change < 11 seconds with Flame Arrestors
Combustibles & Hydrocarbon: 90% of a step change < 20 seconds with Flame Arrestors

Aspirator Air Requirements

3 SCFH Typical at 3 to 6 psig, Instrument air or Nitrogen

Analog Output

Three isolated linear current outputs for O2, combustibles and hydrocarbon. Each output can be 4-20 mA, 0-20 mA, 20-4 mA or 20-0 mA and is fully scalable. NAMUR Configurable. Hold or track during calibration. Max. load 1200 Ω


Five independent, NO alarms
Set relays to energize or de-energize on alarm

Contact Rating 0.5A, 30V, 10VA max. non-inductive load, AC or DC
Digital Communication 2 wire MODBUS RTU, 57.6 KBaud

MODBUS RTU, AMETEK configuration software, or AMEVision HMI


Low Sample Flow, Cell & Detector age tracking, Cell resistance, Calibration required, Analog current verification


Calibrate or verify calibration. Stored calibration and verification data. Selectable calibration gas run time and process recovery time. Timed automatic calibration with optional Remote Calibration Unit.

Sample Pressure ±6 in. water gauge
Max. Sample Dewpoint 392°F (200°C)
Max. Flue Gas Temp. / Probe Type / Lengths

1300°F (704°C) / 316 SS / 36” – 108”(91 cm – 274 cm)
1875°F (1024°C) / 310 SS / 36” – 108”(91 cm – 274 cm)
3000°F (1648°C) / Hexoloy® / 24” – 72” (60 cm – 182 cm)


Ambient Temp.: -25°C to 65°C
Relative Humidity: 5% to 95%, non-condensing


Hinged IP65 (NEMA 4X), weather resistant, stainless steel, explosion-proof, purged, and floor mount versions available.
UL Class I, Div II, Gp B, C, D or ATEX Zone 2, T3 with Purge

Power Requirements

115 VAC, ±10%, 47-63 Hz, 740 VA max.; 230 VAC, ±10%, 47-63 Hz, 740 VA max.

Calibration Gas Requirements

Use calibration gases @ 10 psig, 1.5 SCFH (0.7 L/min.)

O2 Span Gas: Air or from 1.0% to 100% O2, balance N2
O2, Comb. & CH4 Zero Gases: From 0.1 to 10% O2, balance N2
Comb. Span Gas: 60 to 80% (PPM ranges) or 40% to 60% (% ranges) of the selected comb. recorder output range in certified equal mixtures of CO + H2, 3-4% O2, balance N2
Hydrocarbon Span Gas: 2% CH4, 8% to 10% O2, balance N2