Emission measurement on combined heat and power systems

Combined heat and power plants (CHP) are used for the central production of and supply with power and heat. These plants are used in agriculture, in communes, in the management of residential buildings by medium-sized commercial and industrial companies, as well as by municipal utility companies and large energy suppliers.

The conditions for operating a CHP system are better now than ever before. For one thing, low oil and gas prices as well as state subsidies make the investment worthwhile. Apart from this, the increased electricity requirement of a growing world economy must be covered.

In order for a cogeneration plant to be operated economically, certain basic standards must be ensured by the targeted application of suitable measurement technology.

  • Monitoring emission limit values
  • Checking and inspecting engine efficiency
  • Correctly configuring the relations between ignition timing, excess air etc. of the engine
  • Testing of exhaust gas treatment systems

The challenge

The emission analyzer testo 350 at 2G Energy

Combined heat and power plants are usually modified and enlarged engines from automotive engineering which draw in a combustion gas (e.g. landfill gas, biogas or liquid gas), mix it with air, compress it and burn it. During this process, air surplus, fuel pressure, engine setting and ambient temperature or humidity can have a significant effect on the emissions. These effects must be taken into account when optimizing or adjusting the engine, in order to achieve a maximum efficiency of the process as well as a minimum emission level.

If the adjustment is carried out using an imprecise measuring instrument, it can have negative consequences:

  • Misfiring
  • Mechanical knocking
  • Increased temperature in the engine components and operating materials
  • Increased wear
  • Higher service and repair costs

Application sketch

The emission analyzer testo 350 in application

Interested? Download the most important information for the CHP application now:

  • Emissions development (Lambda)
  • Optimum engine settings

The solution: testo 350 emission analyzer

The emission analyzer testo 350

The emissions analyzer testo 350 has application-specific setting menus, which adapt to the respective applications (e.g. λ ≤ 1 or λ > 1 engines), and support the user in various ways. In combination with the high-performance Peltier gas preparation, the testo 350 provides highly accurate measurement values in the shortest possible time.

The advantages

  • The system's fuel consumption can be reduced by up to 10 %.
  • Increased engine life
  • Lower maintenance costs thanks to monitoring of mechanical wear
  • Provable quality of service work thanks to documented measurement values

Reference report testo 350

The emission analyzer testo 350 at 2G Energy AG

How is the efficient operation of a CHP plant guaranteed with the emission analyzer testo 350? Find out more from the practical example of 2G Energy AG.

Download: Reference report 2G Energy AG

The alternative: testo 340 emission analyzer

The emission analyzer testo 340

The testo 340 is the low-cost alternative with very precise measurement technology and an especially robust design. For highly accurate results in measurements without gas preparation.

The advantages

  • Self-cleaning effect in the special hose (PTFE): condensate and dirt particles do not adhere
  • Easy setting: the hose extension (up to 7.8 m) means you can see the measuring instrument display even in measuring locations which are a long way away
  • Measuring range extension (factor 5): unrestricted measurement of high concentrations (CO up to 50,000 ppm)
  • Suitable for use with biogas and the measurement of SO₂ and H₂S

Reference report testo 340

Reference flue gas measuring instrument testo 340

Cummins is one of the world’s leading manufacturers of diesel and gas engines. The company relies on the testo 340 when commissioning them. Read here what the experts love.

Versatile measurement technology for combined heat and power plants

Preventive maintenance


  • Safe testing of electrical and mechanical components during continuing operation
  • Fewer downtimes, longer product life and more efficient energy use.

Measurement of temperature, humidity and flow velocity

  • Optimization of the heat exchanger
  • Extension of the life of the turbocharger

Measuring electrical measurement parameters

  • Monitoring of electrical components in order to minimize breakdowns

Brochure: Measurement technology for CHP

  • Condensed selection of technology for CHP pros
  • With new kits for emission analysis