PEMS stands for portable emissions measurement system. It is a compact suite of gas analyzers and flow meters strapped to a vehicle to monitor tailpipe pollutants like nitrogen oxides and particulates outside of a laboratory. Engineers and regulators use this equipment to verify that a vehicle meets emissions standards under actual dynamic loads, preventing the use of defeat devices tailored for stationary dyno tests.
We need to run a PEMS validation on the new diesel calibration to make sure the NOx levels stay legal on a cold start.
Also heard as
- portable emissions measurement system
Related terms
Diesel particulate filter
An exhaust component that traps and periodically burns off soot from diesel emissions.
Catalytic converter
An exhaust emission control device that reduces toxic gases and pollutants into less harmful compounds.
DEF
Diesel exhaust fluid is a urea-based solution injected into the exhaust stream to reduce nitrogen oxide emissions.
Dyno
A dynamometer used to measure engine power and torque output.