ENDA-5000 Stack Gas Analysis System

Continuous simultaneous and high-precision measurement of NOx, SO2, CO, CO2 and O2

HORIBA has over 100,000 CEM systems installed and 30 years of quality and experience. That is the base on which HORIBA’s new ENDA-5000 series of stack-gas analysis systems are built. These systems have a small footprint and use cross-flow modulated non-dispersive infrared (NDIR) and magneto-pneumatic detectors that are inherently drift-free. The ENDA-5000 series are superior continuous analysis systems that perform reliably for difficult exhaust gas measurements, when measurement errors cannot be tolerated. This CEM series features a new intuitive touch panel that makes every operation available with the touch of a single button. The ENDA-5000 series systems are also designed for ease of maintenance. They are ideal for a variety of uses, including emissions monitoring from steam boilers, refuse incinerators, and electric power generation plants to assure pollution standards are being met.


  • Long-term stability : Cross-flow modulated non-dispersive infrared (NDIR) detection is renowned for long-term stability
    1. No need for optical adjustments
      With  NDIR, the sample gas and reference gas are intromitted into a single measurement cell alternately to obtain modulation signal. Therefore there is no need to adjust two different optical paths so that they are balanced.
    2. A stable zero point
      Since ENDA-5000 series output the difference between the measured gas and the reference gas each time measurement occures (once a second), the zero point is extremely stable.
    3. Continuous cleaning keeps the cell clean
      Since cleaning air is fed into the sample cell in between each batch of sample gas, the cell resistes contamination and normally remains clean.This reduces span drift and makes the equipment safe and stable for long periods of time.
  • Compact : Body yields wider maintenance area
    ENDA-5000 series can be installed almost anywhere, with ample room on all sides for easy access and much easirer maintenance.
  • Easy to use : Features an intuitive touch panel
    The operator can easily switch between the corrected and converted density settings screens or view alert information with touch of a single button.


Measurement methodsNDIRNDIRNDIRNDIRMagneto-pneumatic detection
Range*2Standard200~5000 ppm200~5000 ppm200~5000 ppm5~25 vol%10~25 vol%
Option100 ppm~50 ppm~100 ppm~
Range RatioWithin a factor of 10Within a factor of 10Within a factor of 10Within a factor of 5Within a factor of 2.5
RepeatabilityWithin 0.5% of full scale/week (with optional range, or during O2 measurement, ±1.0% of full scale/week)
Linearity (indicator error)±1.0% of full scale
Zero drift±1.0% of full scale/week (assuming surrounding temperature is maintained within 5 °C)
(with optional range, or O2 measurement, ±2.0% of full scale/week)
Span drift±2.0% of full scale/week (assuming surrounding temperature is maintained within 5°)
Response time*3Within 60 seconds (Td + T90 from equipment intake area) (sample flow 0.6 L/min.) (within 240 seconds for SO2 only)
Overall interference from co-existing gases±2.0% of full scale (within standard range, with standard gas formation)
DisplayTouch panel LCD (backlight) (four usable lines)
Temperature-5 to 40 °C (away from direct sunlight and radiation heat )*4
Humidity85% or less (no condensation)
Vibration100 Hz, 0.3 m/s2or less
DustStandard environment or better
Measuring Gas ConditionTemperature250 °C or lower
Dust0.1 g/Nm3 or less
Standard gas composition*5NO: 500 ppm or less; NO2: 15 ppm or less; SO2: 1000 ppm or less; SO3: 50 ppm or less;
CO: 200 ppm or less; CO2: 15% volume or less; H2O: 20% volume or less
Sampling methodDry sampling using an electric cooler
Sample gas flow2.5 L/min~3.0 L/min
Sample inlet tubeTeflon tubing (Ø8/Ø6 mm)
Sample gas pressure±4.9 kPa (three points selected)
(with no sample gas back pressure)
(1) -1.96 to 4.9 kPa
(2) ±3.43 kPa
(3) -4.9 to 1.96 kPa


Pressure controlPressure control uses a regulator and pump; Reduced pressure sampling; Control pressure: -4.9 kPa
OutputDC 4 to 20 mA (absolute output) (DC 0 to 16 mA/DC 0 to 1 V/DC 1 to 5V optional) Max. 12 output systems
External outputAnalysis alerts, analysis warnings, range display, corrections, conservation, purging (option)
Contact capacity: DC 30 V 1 A, AC 250 V 1 A resistance load
Correction methodDry correction, automatic correction (correction cycle: 7 days standard, can be adjusted to between 1 and 99 days), manual correction
Calibration gasZero gasWith measurement method authorization: N2, When there is no measurement method authorization: N2 or ambient air
O2 carrier gasAmbient air
Span gasGas cylinder for each component measured (when there is no measurement method authorization: O2 or ambient air can be used)
Probe collection point filterFlange: JIS 10K, 40 AFF; Sample probe tube length: 1000 mm; Material: SUS-316 stainless steel;
Filter element: SUS-304 stainless steel and 2um-pleated quartz wool; Electric heater: 100 VA, with water droplet proof case
Power supplyAC 100 V ±15 V(85 V~115 V)
Power frequency50/60 Hz (switchable)
Power consumptionAbout 800 VA (heated piping 30m: +1100 VA; heater in tray: +300 VA)
Exterior dimensions/Mass600 (W) x 1770 (H) x 300 (D) mm (high pressure gas cylinders, 3.4 L cylinders, maximum of 3 cylinders); About 180 kg (not including cylinders)
600 (W) x 1770 (H) x 300 (D) mm (high pressure gas cylinders, 3.4 L cylinders, maximum of 3 cylinders); About 200 kg (not including cylinders)
Materials in contract with sample gasSUS-316 stainless steel, SUS-304 stainless steel, Teflon, polypropylene, polyethylene,
flourorubber, PVC, PVDF, and glass
EnclosureIndependent outdoor installation
Plate thickness: Main unit, doors, top plate, steel plate: 2.3 mm; Channel base: 3.2 mm; Doors: front opening; Interface: right front
Color/FinishSemi-gloss Munsell 5Y7/1 on all inner and outer surfaces

*1: No carrier gas cylinder is required.

*2: Up to two ranges are supported for each component.

*3: Response time may vary depending on the sampling system composition.

*4: Support is available for -15 to 40 °C (cold-climate version) and 5 to 50 °C.

*5: An NH3 scrubber is available as an option for cases where a combined gas includes NH3. SO2 measurement corrected for CH4 interference is available for cases where there is CH4 in the sample gas for SO2 measurement. CO measurement corrected for N2O interference is available for cases where there is N2O in the sample gas for CO measurement.

Horiba instrumentsMore cems




CO – Carbon Monoxide, CO2 – Carbon Dioxide, NOx – Nitrogen oxides, O2 – Oxygen Gas, SO2 – Sulfur dioxide




Magneto-pneumatic, NDIR


CEMS, Stack Gas analysis


Bio Energy, Chemical, Petrochemical, Power Plants, Pulp & Paper, Refinery, Steel Plants