Electrostatic sensing of particulates provides the most robust and cost-effective in-situ measurement of particulate matter available in the market today. With proven resolution to less than 0.5 mg per cubic meter, ePM/PMTrac® is ideal for any application in which quantification of near-zero PM or PN is required.  

Research & Advanced Engineering

Explore research papers that delve into the cutting-edge performance of EmiSense Technologies' state-of-the-art real-time sensors. Explore in-depth analyses, including "Evaluation of an On-Board, Real-Time Electronic Particulate Matter Sensor Using Heavy-Duty On-Highway Diesel Engine Platform," a SAE Technical Paper, and other relevant publications from the Journal of Aerosol Science. Gain valuable insights into the accuracy, reliability, and innovative applications of our sensor technology.

  • The basic sensor is a high voltage (~1kV) concentric electrostatic trap. Field directed assembly of soot dendrites result in an equilibrium in which highly charged soot agglomerates exit the sensor, and the charge loss is proportional to particulate matter mass concentration (PM) or Particulate Number (PN). Aerosol Scientists from Ford Motor Company have published a good paper on the measurement principle, and more recently further study of application for monitoring particulate filters.

  • Both independent labs and OEMs have done extensive testing of the ePM technology, establishing very high levels of correlation to reference instruments. One recent technical paper of interest is SAE 2020-01-0385: Evaluation of an On-board, Real-time Electronic Particulate Matter Sensor Using Heavy-duty On-highway Diesel Engine Platform. Much of the testing work done by private companies or closed consortiums is not available for public disclosure. However, evaluation kits are available for purchase directly from Emisense.

  • While current generation resistive accumulator sensors are used for existing OBD applications, it is doubtful that they will perform well in next-generation applications. For GDI, China-6b, Euro-7, and higher CARB performance ratios, in-situ sensors need to combine a low detection threshold with good accuracy and response time. Only PMTrac® ePM technology can achieve this combination.

  • The ePM / PMTrac® technology portfolio has recently been licensed to a global Tier-1 Supplier, with exclusivity for the automotive field of use. Samples will be available in the 2nd half of 2025, with serial production slated to begin in 2028. Emisense has developer’s kits available, suitable for evaluation of the measurement principle and OBD integration work, but not suitable for serial production. For non-automotive applications, samples, productions partnerships, and licensing remains available.

Hear From Those Who Know

  • “Besides the high sensitivity, ePM sensors are useful because of the continuity of signal. This enables continuous monitoring of very low levels of ultrafine particle emissions, and greatly simplifies the signal processing required to interpret the sensor signal.”

    -Prof. Kent Johnson, Ph.D., Principal Investigator, Emissions and Fuels Research, UC Riverside

  • “The Emisense PMTrac® technology is greatly needed- not just in passenger vehicles, but also in marine, non-road vehicles, and stationary combustion applications. As long as clean combustion is playing a role, it should be as near-zero as possible from an emissions perspective.”

    -Emissions and Mobility Regulatory Consultant

  • "PM filters work so well that the air coming out of the tailpipe can be “cleaner” than the ambient air in a community. But you have to make sure they are working properly for the life of the application. This is why reliable, sensitive, and durable ePM sensors are of such value."

    -Combustion Institute Engineer