Tutorial: Aerosol Measurements - Principles, Techniques and Application to Brake Emissions

The proper measurement and assessment of brake emissions is a challenge to traditional testing in many aspects. First, the analysis itself can involve over 100 data channels for a single brake. Besides, the orders of magnitude are much larger or significantly smaller, compared to legacy brake tests, from measuring distances in millimeters to measuring particles in nanometers (one-millionth of a millimeter). And, from counting items in hundreds (degrees of temperature or braking events) to counting particles in millions, or tens of millions for particles on a single particle size bin during a brake test. This tutorial helps the audience navigate through brake emissions data, make sense of its meaning, and make better decisions for a vehicle, a system, or a component program. The tutorial (using examples and real time measurements) explains critical concepts related to particle mass (PM), particle number (PN), size distribution, and new particle formation process. The second part describes the measurement techniques and principles of PM, PN, Particle Size Distribution (agnostic to system supplier, integrator, and duty cycle). The final section of the tutorial provides insight into the standard and acceptable metrics to report particulate matter behavior and characteristics