Mk8 EGA: Exhaust Gas Analysis

Overview: CEMS emissions auditing and trim control

For decades, boilerhouses have used our EGA’s to monitor flue emissions to comply with environmental regulations & to reduce fuel usage & emissions. The EGA’s readings feed back to the MM Controller, allowing the MM to adjust the fuel/air ratio (trim) of the burner for optimised performance.

  • Simultaneous & continuous sampling of up to 6 exhaust gases (O2, CO2, CO, NO, NO2 & SO2) at a fraction of the price of alternative systems. Use with Autoflame MM Controller or Standalone Mode.
  • Enables 3 parameter trim control in MM Controller for improved fuel efficiency and emission reduction

With built-in CEMS Auditing software, view reports by user-definable time periods (24 hours, 2 weeks, 1 month, 2 years, etc) based on:

  •  Total weight & volumetric emissions
  • Weight/volumetric emissions per exhaust
  • Total cost of fuel




    • Continuous Emissions Monitoring System (CEMS) for display & data trending
    • Specifically designed for current regulations on emissions monitoring
    • Simultaneous & continuous sampling of up to 6 exhaust gases: O2, CO2, CO, NO, NO2, SO2
    • 10.4” Full colour touch screen
    • Stored information is updated every minute
    • Online monitoring of cell status to identify cell replacement requirement
    • MM Controller or Standalone Operation modes
    • Complete diagnostic information
    • Quick & easy installation using plug-in connectors
    • Designed to minimize maintenance
  • Six 4-20mA analogue outputs of all combustion data for remote logging, printing or chart recording
  • Standard alarm conditions for cell failure, probe blockage & analyser failure
  • Via the Autoflame Mk7 Data Transfer Interface (DTI), all CEMS data from EGA can be communicated & transferred to a Building Management System (BMS) via Ethernet connection/RS422
  • Online manual & user guide
  • Cells contain calibration data and serial number for easy cell replacement
  • Automated cell calibrations on bottled calibration gas (EPA version of EGA)



It is recommended that the EGA is sent back to Autoflame for full service & recalibration every 12-18 months if firing on gas or 9-12 months if firing on oil. System includes reusable packaging to simplify shipping.

Online Data Logging & Historical Trending

  • All of the data that is recorded in the Mk8 EGA can be displayed on the touch screen & through the Mk7 DTI. The resulting data & screens can be outputted for printing/hardcopy records. This data can be exported in real-time for further management, manipulation & adjustment to suit the user’s requirements.
  • Online trending & logging of all combustion parameters, including totalised values
  • Online data is updated every second
  • Historical data is updated every minute & hourly averages are taken
  • User-selectable time function to view historical data, e.g., monthly, weekly, daily, hourly
  • Two years of data stored within the EGA including gases, pressures, atmospheric pressure, temperatures, efficiency, fuel usage

CEMS Auditing


  • Ability to input accurate fuel composition data to improve CEMS analysis
  • 4-20mA input from a fuel flow meter for accurate fuel usage in CEMS calculation
  • View reports by user-definable time periods (6 hours, 8 days, 500 days, etc.) based on:
    • Total weight & volumetric emissions
    • Total cost of fuel (calculated by current cost per tonne of fuel)
    • Weight & volumetric emissions per exhaust gas (O2, CO2, CO, NO, NO2, SO2) & per fuel


Operation with Autoflame MM Controller

  • By connecting the Mk8 EGA to an MM Controller, all of the following functionality is available for improving combustion performance, reducing energy costs & improving safety:
  • The EGA enables Autoflame’s unique 3 parameter trim. The system sends output signals based on three exhaust gases (O2, CO2, & CO) to enable the MM Controller to perform trim. Controller will impose small corrections to the air damper or Variable Speed Drive in order to maintain optimum combustion performance for the system. These minute changes ensure that the original commissioned combustion data is maintained irrespective of changes to stack pressure, barometric pressure & temperature.
  • The MM Controller may be set with upper & lower limits on O2, CO2, CO, NO & exhaust gas temperature. The system can be optioned so that a lockout occurs when limits are exceeded.
  • Additional Components:
    • Includes exhaust gas sampling probe complete with internal filter, thermocouple and sampling tube
    • Optional environmental enclosure available for non-standard conditions, harsh environments
    • Optional external filter available for high condensate fuels or humid environments

Technical Specification

  • Power Supply: 110 - 240V, 50 - 60Hz
  • Ambient Temperature Limits: 5°C(41°F) to 40°C(104°F)
  • Environmental Rating: IP20 NEMA1
  • Gas available: O2, CO2, CO, NO, NO2, SO2

Improvements over Mk7 EGA

Key Points

  1. Retains 2 years of exhaust and fuel consumption data.
  2. Plug-and-play cell replacement (no typing in codes).
  3. CEMS data logging and analysis within the EGA is now standard.


  1. Design of case has been changed to reduce overall dimensions while maintaining internal space.
  2. External filter has been redesigned to increase filter material area.
  3. Connectors have been replaced with screw type fitting. (flying leads)
  4. Additional External filter power connector has been added.

PCB Assembly

  1. PCB design has been reduced from two boards to a single board.
  2. Main processor has been changed to a dual core processor designed with safety certification.
  3. PROM has been removed; software updates will now be via the display SD card.
  4. New pressure sensor hardware with digital interfaces to reduce noise.
  5. Chiller In/Out/Block and cell temperature sensors have been changed for improved accuracy in the low temperature range.
  6. Fuel select lines are now low voltage rather than mains. This means all connections in the secondary connector are low voltage.
  7. Fan has speed read back so that a blocked fan can be detected.


  1. Cell details have been improved to show cell serial number and cell life %.
  2. Cell calibration history is now accessible from the home screen by clicking the cell images so that the lifetime graph can be viewed on a standard EGA.
  3. Completely new Errors based on the new hardware design. A number of errors have also been reduced to Warnings that allow the unit to continue running.
  4. EGA implements calibration drift storage and error reporting in line with EPA CEMS requirements.
  5. An option for remote inlet air temperature sensing has been added.  When enabled data from the internal ambient air temperature sensor is replaced by readings from the third thermocouple connector.  This is enabled with the option “Enable Pre-heat Sensor”.


More About Autoflame EGA’s

The Autoflame Exhaust Gas Analyser (EGA) has been designed to be a cost effective, low maintenance analyser specifically for boiler applications. Developed over 20 years, the EGA system measures O2, CO, CO2 and NO as standard with additional upgrades enabling the measurement of SO2 and NO2. Through its innovative user interface the analyser will clearly display its operational status, alarm conditions and when it is scheduled to be serviced.

When combined with an Autoflame burner control, the system can be set up to carry out combustion air trim.

Mk8 EGA with optional cabinet cooler

Using an innovative three parameter system to monitor O2, CO2 and CO emissions simultaneously, the system will make minor adjustments to the air damper or variable speed drive controlling the delivery of combustion air to maintain the as commissioned optimum performance. Variations in combustion characteristics and the corresponding reduction in combustion efficiency caused by changes in barometric conditions, stack pressure, fuel pressure etc. can be completely counteracted. Fuel savings in the region of 2-4% are typical, with higher savings seen on a number of applications.

The EGA has been used at the heart of a number of innovative emissions monitoring solutions. Systems have been set up to monitor alarm, and in some cases shut down a burner whenever NOx or CO emissions exceed required levels. Where used in conjunction with an Autoflame data transfer interface, users have been able to carry out continuous emissions monitoring, logging historical data to satisfy local statutory requirements. The latest developments of the EGA product line include revisions to include a touchscreen user interface and MCERTS approval.

To learn more about the benefits of installing an Autoflame EGA on your boiler, please contact a member of Autoflame’s technical sales team.