Emissions Equipment

We manufacture portable emission sampling systems. We offer equipment for sale, equipment for rent, equipment training and support services, and equipment design services. We work in partnership with Waltech Systems. They provide valuable design input and they manufacture our circuit boards.


The Ratnoze sampling system is specialized for characterizing the climate impact of combustion emission sources that have high particle emissions, large emission fluctuations, and are located in remote areas, such as wood stoves, brick kilns, charcoal kilns, burn piles, biochar makers, and diesel engines. The dilution system conditions the emission sample for more representative partitioning of semi-volatile species, such as organic carbon. The real-time sensor data series show emission fluctuations, and the low sample flow rate facilitates long-term sampling to capture full burn cycles. The Ratnoze is a complete sampling system including sampling probes, accessories, and data analysis software.


A fully loaded Ratnoze is very versatile, and suitable for a wide range of combustion emission sources; small, large, clean, dirty. Tell us what you want to measure, and we will give you a quote for a sampling system that balances functionality, cost, weight, and size to meet your needs.


The Ratnoze5 (constructed in 2021) is housed by the Pakistan Ministry of Climate for measuring brick kiln emissions in partership with ICIMOD. 


The Ratnoze4 is currently in use by MAE to measure emissions of cooking and heating stoves, brush piles, and biochar kilns.

Improvements from Ratnoze3 include:

  • real-time particle light absorption by Brechtel TAP
  • methane sensing
  • new probe design to reduce particle loss and condensation

This poster is about the Ratnoze4 before the methane sensor was added.


The Ratnoze3 was constructed in 2017 for the Beijing University of Business and Technology. Improvements from Ratnoze2 include:

  • added auxillary gas sensor board: electrochemical sensors for H2S, NO, NO2, O2, and PID sensor for hydrocarbons
  • added absolute ambient pressure sensor for automatic pressure corrections
  • firmware: easier to update calibration parameters
  • better probe design to trap condensation


The Ratnoze2 was constructed in 2016 for the Colombia brick kiln emissions project. It is housed at CAEM in Colombia where it is still in use measuring brick kiln emissions. Improvements from Ratnoze1 include:

  • more rigid sampling probe
  • better MicroAeth sample train


The Ratnoze1 was constructed in 2016 for the South Asia brick kiln emissions project. The Ratnoze1 is an evolution of Dr. Tami Bond's portable emission sampling systems at University of Illinois, most notably the sampling system for brick kilns made by Dr. Cheryl Weyant described here. Ratnoze1 is housed at ICIMOD in Nepal where it has been used to measure emissions from many brick kilns in India, Nepal, and Pakistan, as well as diesel water pumps and diesel vehicles.


Publications by ICIMOD:

Brick kilns: Nepal,2019

Diesel water pumps: Adhikari,2019

Diesel vehicles: Mool,2020

Diesel vehicles: Das,2022

Musakonak Gobargas

Musakonak gobargas is Nepali for Ratnoze Biogas. It is a Ratnoze sensing platform configured with sensors to measure biogas flow, pressure, and compositon (CH4 and CO2) to run alongside the Fumitron in the Nepal biogas emissions field campaign.


The Fumitron is a portable sampling system that was developed and constructed at University of Illinois in Dr. Tami's Bond's laboratory in 2015. One Fumitron is housed at CRT/N in Nepal, and two other Fumitron's are collecting dust somewhere in the U.S. The Fumitrons have been used in several field campaigns measuring cooking and heating stove emissions in Nepal, Alaska, and China. These field campaigns served as valuable field tests of the Fumitron (with sucesses and failures) that benefited the Ratnoze design.

Gobargas Flow Monitor

Gobargas is Nepali for biogas. The flow monitors were constructed to log biogas energy consumption during a Kitchen Performance Test in Nepal. The monitor consits of an Arduino Due and a Waltech shield with SD card logger connected to a battery and mass flow sensor (some also have a pressure sensor). The monitors were installed inline with the biogas hose next to the stove, and they ran for 3 days on one charge. The flow monitor data also revealed several maintenance issues with biogas systems, such as leaks and clogged stoves. The flow sensors were replaced after one year, because the biogas corroded the hot wire filaments. A different type of flow sensor could last longer.