Temperature and Inflation Pressure Effects on Airborne Tire Wear Particle Measurements on a Chassis Dynamometer

Airborne tire and road wear particles (TRWP) are gaining regulatory attention, but laboratory methods for their measurement are not yet standardized. This study aimed to quantify how controllable chassis-dynamometer operating parameters affect airborne TRWP measurements and to identify the operating limits of the DLR TRWP-Measurement System. A two-level factorial design in tire inflation pressure (1.8/3.8 bar) and chamber temperature (11/35 °C) was realized in two sequential blocks at rear-wheel toe settings of 48′ and 30′, bracketed by reference measurements. Particle number was measured with a condensation particle counter (MCPC, 7 nm–2 µm) and an optical particle sizer (OPS, 0.3–10 µm), from which an optical mass proxy was derived. Higher chamber temperature increased the cumulative MCPC response by a factor of 3.6 (95% CI 1.8–7.2), whereas higher inflation pressure reduced the OPS number response by 18% (95% CI 12–24%); the OPS mass proxy decreased by approximately 17% with temperature. Toe settings above 48′ caused progressively rising particle signals and irregular tread wear. The MCPC response under reference conditions doubled over the campaign, showing that drift monitoring and blocked, randomized run orders are prerequisites for factorial airborne TRWP testing.