PEMS Measurements

Interest in performing engine exhaust measurements on-board a vehicle instead of a dynamometer is continually growing as the emissions from engines have been found vary depending on the environmental and driving conditions. On-board measurements give better information on real-world emissions when the driving conditions and vehicle speed are not strictly controlled. The requirements for measurement instruments, however, are quite different in PEMS measurements compared to well controlled test cell conditions. Typical additional requirements include low power consumption and insensitivity to vibration and varying environmental conditions.

Dekati® Solutions for PEMS measurements include:




High Temperature ELPI®+ is a real-time measurement instrument for measuring PM emissions from diesel and gasoline vehicles in both dynamometer as well as in on-board conditions. The High Temperature ELPI®+ is especially designed for high temperature emission measurements and allows direct sampling from tailpipe conditions from up to 180 °C.

HT-ELPI®+ features:

  • Real-time particle size distribution and concentration 6 nm - 10 µm
  • 10 Hz sampling rate for detecting small timescale changes in the sample
  • Direct sampling from up to 180 °C
  • Independent stand-alone operation or control via laptop using ELPI+VI software
  • Analogue inputs and outputs for data integration
  • Wide operation concentration range suitable for both low and high concentration measurements
  • Robust and easy-to-use system

The HT-ELPI®+ system is set up in directly in the tailpipe measurement with a heated sampling line provided with the HT-ELPI®+. Alternative, well-designed sample conditioning system can be placed between the tailpipe and HT-ELPI®+. Depending on the exhaust conditions the setup can be e.g.