CEMS solutions

Your Benefits

  • Rapid condensation technology removes water from gas to minimize loss of SO2
  • Automatic drainage into a liquid storage tank reduces environmental pollution
  • Membrane filter protects the safety of the analysis chamber
  • Compatible with a variety of transmitter signals
  • Can coordinate with the SMC900 data processing system to process collected data
  • Gas lines are thermally insulated so that no condensation occurs during the transport of sample gas

The exact device specifications and performance data of the product may deviate from the information provided here, and depend on the application in which the product is being used and the relevant customer specifications.


The SMC9021 was designed according to the HJ/T-76-2007; HJ/T-75-2007 standards for use as a continuous emission monitoring system of flue gases. The gas monitor uses the direct extraction method, and the heated filter sampling probe has a connector for automatic back-purging. The sample line self-regulates its temperature. The monitoring system can receive data from a dust analyzer, temperature/pressure transmitters, and flow transmitters and send it via PLC to data processing equipment. The SMC900 data processing unit can convert gas and solid pollutant data into normalized, dry-basis, oxygen reference converted emissions quantities and then transmit them to the environmental protection authorities.

At a glance
  • The heated sampling probe prevents the flue gas from cooling during the sampling process
  • The sampling probe has back-purge functionality for longer maintenance intervals
  • Supports PLC controlled automatic back-purge, drainage, and calibration to ensure long-term up-time
  • Alarm parameters may be set for temperature, flow rate, and humidity for easy operation of the monitoring system
  • Multiple configurations available (S700 series)
  • Additional measurement capabilities available (oxygen content, dust content, flow rate measurement, etc.)


Technical overview

  • SMC9021 system

    SMC9021 system

    Measured valuesCO, CO2, NOx, O2, SO2
    Performance-tested measurandsCO, CO2, NOx, O2, SO2
    Measurement principlesNDIR spectroscopy, electrochemical cell
    Gas flow rate
    10 l/min ... 60 l/min
    Measuring ranges
    CO0 ... 500 mg/m³ / 0 ... 2,500 mg/m³
    NO0 ... 500 mg/m³ / 0 ... 2,500 mg/m³
    O20 ... 21 Vol.-%
    SO20 ... 500 mg/m³ / 0 ... 2,500 mg/m³
    Certified measuring ranges
    CO0 ... 2,500 mg/m³
    NO0 ... 2,500 mg/m³
    SO20 ... 2,500 mg/m³
    Response time (t90)
    ≤ 15 s
    ≤ ± 1 %
    Of measuring range full scale
    Sensitivity drift
    ≤ ± 1 %: of measuring range full scale per week
    Zero point drift
    ≤ ± 1 %: of measuring range full scale per week
    Reference point drift
    ≤ ± 1 %: of measuring range full scale per week
    Detection limit
    ≤ 1 %
    ≤ 1 %
    Process temperature
    ≤ +300 °C
    Process pressure
    –100 hPa ... 100 hPa
    Ambient temperature
    +5 °C ... +35 °C
    Storage temperature
    –20 °C ... +70 °C
    Ambient pressure
    900 hPa ... 1,100 hPa
    Enclosure rating
    Analog outputs4 outputs:
    4 ... 20 mA
    Analog inputsOptional 2 inputs possible
    Digital outputsOptional 4 outputs possible
    Digital inputsOptional 4 inputs possible
    Dimensions (W x H x D)
    800 mm x 2,100 mm x 800 mm
    ≤ 300 kg
    Power supply
    Voltage220 V AC
    Frequency50 Hz
    Power consumption≤ 2,000 VA
    Instrument air: ≥ 4 bar≤ 100 l/min
    During backflushing
    Sample gas connections
    Sample gas inlet8 mm diameter
    Exhaust gas outlet14 mm diameter
    Auxiliary gas connections
    Instrument airDN 6/8
    Corrective functionsManual or automated adjustment with test gases
    System components

    Gas sampling unit

    Sample gas line

    Analyzer cabinet

    Connection unit

    Integrated components

    Temperature sensor

    Pressure sensor

    Humidity sensor

    Flow sensor


All technical data can be found accompanying the individual product