ISO 21755-1:2019 PDF

Overview

ISO 21755-1:2019 - Motorcycles - Measurement method for evaporative emissions - Part 1: SHED test procedure specifies a standardized method to measure evaporative hydrocarbon emissions from motorcycles using a SHED (Sealed Housing for Evaporative Determination). It applies to motorcycles with spark-ignition engines (four-stroke, two-stroke or rotary piston engines) and is intended for certification, development, research and regulatory testing where accurate evaporative emissions data are required.

Key topics and technical requirements

• Test structure: The SHED test comprises a conditioning phase (test cycle and motorcycle soak) and a test phase (tank diurnal breathing loss, optional running loss during the test cycle, and hot soak loss). Mass emissions from phases are summed to give the overall evaporative emission result.
• SHED enclosure: A gas-tight, hydrocarbon-impermeable measuring chamber that allows access to the motorcycle, pressure equilibration, and controlled internal temperatures (interior surfaces not below 293 K when cooled). Surfaces must be non-reactive to hydrocarbons.
• Analytical systems: Atmosphere monitoring via a flame ionisation detector (FID) hydrocarbon analyser. Key analyser specs include response time to 90% of final reading