The IECOAL4000 flue gas analyzer (fixed combustion gas analyzer) continuously measures CO in the flue gas of boilers, incinerators and drying systems. It measures CO from 0–4000 ppm with 1 ppm resolution and linear 4–20 mA output, with an integrated sample extraction, dust filtration, cooling and automatic condensate drain system. In addition to CO, NO, NO₂, SO₂ and O₂ channels can be added on request for emission monitoring and combustion optimisation.
The complete system is housed in an IP54 wall-mounted steel cabinet (600 × 500 × 240 mm) with front status lamps, and is supplied with an FT105 sampling probe mounted directly on the stack. It is designed, supplied and commissioned by Equipment Industrial Solution Co., Ltd (ISE) for boiler operating conditions in Vietnam and Southeast Asia.
Measured gases
| Gas | Configuration | Details |
|---|---|---|
| CO (carbon monoxide) | Standard | 0–4000 ppm, 1 ppm resolution, electrochemical sensor, 4–20 mA output |
| NO (nitric oxide) | Optional | Electrochemical sensor, 4–20 mA output, range configured to application |
| NO₂ (nitrogen dioxide) | Optional | Electrochemical sensor, 4–20 mA output, range configured to application |
| SO₂ (sulphur dioxide) | Optional | Electrochemical sensor, 4–20 mA output, range configured to application |
| O₂ (oxygen) | Optional | 4–20 mA output, excess oxygen for air-fuel control |
Each optional channel has its own 4–20 mA output. Ranges for NO, NO₂, SO₂ and O₂ are configured to fuel type and monitoring requirements – contact ISE for advice.
Design and operating principle
Continuous-flow sampling: a long-life vibration pump draws gas steadily from the stack into the analysis chamber, keeping measurement stable even when stack draft changes or filters and lines become dusty or wet.
Filtering and cooling: the gas passes a filter and is cooled; condensate is separated by a coalescing filter, then the gas is dried and cleaned of particles by a second filter before entering the analysis chamber.
Condensate drain: condensate at FILTER 01 drains by gravity and is emptied manually at weekly checks; condensate at FILTER 02 is pumped out automatically by PUMP02, with manual drain via VALVE01.
Pre-calibrated analysis chamber: the electrochemical CO sensor is mounted on the chamber with its calibrated electronics alongside. Sensor life is about 2 years; at end of life the pre-calibrated sensor-and-board assembly is simply replaced.
High-CO sensor protection: when CO exceeds 1500 ppm (default), the red High Level lamp lights, SOLENOID01 switches and the system draws ambient air to dilute CO; measurement resumes when CO falls to 1200 ppm. This prevents prolonged over-range exposure and extends sensor life.
Status lamps: High Level (red) – over setpoint; Air Pump (green) – gas pump running; Water Pump (green) – drain pump running.
Boiler flue gas analysis system diagram
Flue gas from the furnace passes the cyclone; the FT105 probe samples before the ID fan and the gas is piped to the IECOAL4000 cabinet. The analyzer receives an ID-fan contact signal, is powered from 230 VAC/50 Hz and outputs 4–20 mA to the PLC or monitoring display.
FT105 sampling probe and accessories
The analyzer is supplied with the FT105 sampling probe, dust filter bag and hose clamps. The FT105 mounts directly on the stack via a JIS10K DN20 (¾”) flange.
IECOAL4000 flue gas analyzer specifications
| Parameter | Value |
|---|---|
| Measured gases | CO (standard); NO, NO₂, SO₂, O₂ (optional) |
| CO range | 0–4000 ppm |
| CO concentration limit | 5000 ppm |
| Resolution | 1 ppm |
| Response time (T90) | < 20 s |
| Long-term drift | < 2 % per month |
| Repeatability | 1 % of signal |
| Calibration | Certified calibration gas (approx. 800 ppm CO in N₂) |
| CO sensor life | Approx. 2 years |
| Sensor operating temperature | −5…+40 °C |
| Output | Linear 4–20 mA, 2-wire |
| Alarm / protection threshold | Default 1500 ppm, resume at 1200 ppm |
| Power supply | 230 VAC +10 % / −15 %, 50 Hz |
| Max. power consumption | 15 VA |
| Cabinet (H × W × D) | 600 × 500 × 240 mm, IP54 |
| Weight | Approx. 18 kg |
| Mounting | Vertical wall mounting near the boiler stack |
| Operating environment | +5…+55 °C, 15–95 % RH |
| Storage environment | −20…+60 °C, 15–98 % RH |
Installation and wiring
- Install the cabinet near the boiler where ambient does not exceed 55 °C.
- Mount the FT105 probe on the stack about 2 pipe diameters from any expansion joint.
- Recommended maximum sample line length between cabinet and FT105: 10 m.
| Terminal | Connection | Cable |
|---|---|---|
| L220 / N220 / PE | Phase / neutral / earth | 1.5 mm² |
| L220 (1.220) – L220 (1.131) | ID fan (IDF) dry contact | 2 × 0.75 mm² |
| SIG+ / SIG− | 4–20 mA output | 2 × 0.75 mm² + shield |
Operation and maintenance
- Before start-up: check the FT105 has its dust filter bag fitted and gas flows from the furnace outwards; FILTER 01 drain valve closed, FILTER 02 drain valve open; air pump and water pump ON.
- Check condensate level regularly; inspect and replace FILTER 01 every 1–3 weeks depending on fuel.
- Every 2 months, back-blow with compressed air or replace the FT105 filter element.
- Periodically blow out the sample line and check the condensate drain line.
Applications of the flue gas analyzer
- CO monitoring on coal, wood, biomass, oil and gas boilers – detecting incomplete combustion.
- Combined with O₂ for air-fuel control, combustion optimisation and fuel savings.
- NO, NO₂, SO₂ monitoring for environmental emission control.
- Industrial incinerators, dryers and kilns.
FAQ
Why measure CO in boiler flue gas?
High CO indicates incomplete combustion – wasted fuel, soot and safety risk. Monitoring CO allows timely air adjustment for more efficient combustion.
Can NO, NO₂, SO₂ and O₂ be added?
Yes. Each additional channel has its own 4–20 mA output. Contact ISE for the right configuration.
How long does the CO sensor last?
About 2 years in normal operation; the automatic fresh-air purge above 1500 ppm CO helps extend sensor life.
Related products
- SST OXY-IE boiler oxygen sensor
- Tecnocontrol TS236 / TS237 zirconia oxygen sensor
- Boiler oxygen trim control
Where to buy the IECOAL4000 flue gas analyzer?
EQUIPMENT INDUSTRIAL SOLUTION CO., LTD (ISE) – Ho Chi Minh City, Vietnam – supplies genuine the IECOAL4000 flue gas analyzer with technical consulting, fast quotation and on-site commissioning support across Vietnam and Southeast Asia.
Contact us: Sales +84 909 617 185 – Technical +84 979 117 185 – Email: [email protected]
