Laboratory Emissions Monitoring System (LEMS)

“The Portable Emissions Monitoring System (PEMS) that we acquired from Aprovecho Research Center has proven to be invaluable in our daily activities. In addition to its usefulness in the evaluation of stove models and design modification, the real-time data collection and display allows us to identify influences in fuel feeding during our teaching activities. The portable nature of the equipment allows us to use it in the local communities to evaluate true emissions during normal cooking activities. Finally, the equipment is reasonable in terms of costs which will, perhaps, allow us to purchase an additional PEMS to help us comply with the demand for client evaluations and our student research activities.”

Aprovecho Research Center manufactures and sells the LEMS: the Laboratory Emissions Monitoring System. More than fifteen stove labs around the world use the LEMS, most use it every day to test and improve stoves. The LEMS has been run side by side with the Environmental Protection Agency system and results were comparable.

The solid sheet metal hood and large variable speed blower fan allow the LEMS to accurately measure the emissions of stoves ( CO, CO2, PM2.5, black carbon) ranging from tiny TLUDs to giant institutional stoves. PM 2.5 is measured in real time, and shown on the computer screen, and with pre and post weighed gravimetric filters. The LEMS has been in use for ten years and meets all IWA requirements. Simple upgrades allow for compliance with the recently released ISO standard.

  • A new chimney stove testing cap makes it easier to test chimney stoves.
  • The LEMS now measures black carbon.
  • The new sensor box was re-designed and improved in 2016.
  • The software is also easier to use.

The LEMS manual provides specifics on LEMS design, theory, and operation. See our video gallery for step-by-step videos on how to assemble, use, and calibrate the LEMS.

Contact Sam Bentson for more information.

The LEMS is in use by cook stove researchers around the world.

Data Sheet

The analysis software is written in Excel and uses macros.

USER-DEFINED TESTS – The software can be adapted to suit any test that is desired.

In addition to the standard WBT and CCT, additional emissions outputs include important measures such as:
Emission Factors (per kg or MJ of fuel)
Total Emissions
Emission/CO2 Ratio Benchmark performance level.
Also, a carbon balance is automatically calculated to ensure that measured emissions are in the proper range with respect to the carbon burned in the fuel.
If you have specialized data acquisition needs that further our goals of cleaner air, improved fuel efficiency, and better science for the world’s poor, call or email us for a price quotation on a customized LEMS.
Software –

Data Acquisition software consists of a simple data streaming program and graphing software in Java, provided.

Processing software is written in Visual Basic for Microsoft Excel 2003 for Windows and consists of a simple spreadsheet that incorporates and processes data. A Windows laptop with Microsoft Excel must be available for running the system. Macros must be enabled in the Security settings for software to function.

Calculations are consistent with WBT 4.2.3.

Available add-on options for the LEMS include:

• Filter system for OCEC particle analysis
• Tedlar bag system for analysis of greenhouse gases (such as methane)
• Gravimetric (filter-based) PM quantification
• Contact us for additional option possibilities

The LEMS analysis software is compatible with Windows and can process data from either a Water Boiling Test (WBT) or a Controlled Cooking Test (CCT) using the automated data processing spreadsheets. Personnel with reasonable computer experience can run the LEMS, which comes with a comprehensive instruction manual.

The LEMS can be used for various testing procedures:
WBT – the standard laboratory test for optimizing cooking stove designs.
CCT – Testing what happens when a local cook prepares common meals using both the traditional and improved stoves for comparisons.
QUALITY CONTROL – When many stoves are produced, a random sample can be selected and tested to ensure performance is up to specifications.
CARBON CREDITS – With CO2 measurement built-in, and a methane add-on available, actual emission factors can be measured and used in place of the IPCC defaults when carbon credits are being used. Gold standard has accepted measurements from the LEMS as an excellent alternative to IPCC defaults – which can help to provide higher carbon credits due to more accurate measures of improved stoves.