SAE J2943_202205

This document describes particulate filter weigh-room recommended practices to provide guidance in the procedures and processes associated with gravimetric filter weighing of engine or vehicle particulate matter (PM) emissions. This recommended practice provides proper procedures to build and maintain a particulate filter weigh room or enclosure to meet the requirements of EPA's 40 CFR Part 1065 and ISO 14065 for obtaining low measurement uncertainty. The content of this recommended practice addresses the following areas: a Particulate Filter Weigh Room b Microbalance Requirements c Filter Conditioning and Handling Requirements d Weighing Process e Equipment Calibration and Maintenance Since the introduction of the first particulate mass emissions standard for heavy-duty diesel engines in 1988, engine and vehicle manufacturers have substantially reduced particulate matter (PM) mass emissions from modern internal combustion engines. PM emissions standard levels have decreased from 0.6 g/bhp-h to the current 0.01 g/bhp-h over the U.S. Heavy Duty Federal Test Procedure (FTP). This reduction in PM emissions resulted mainly from improvements in fuel-air combustion, the introduction of high-pressure fuel injection systems, fuel property improvements, and exhaust aftertreatment. PM emissions from an engine or vehicle are measured using particulate matter sample filters. The low PM emissions limits currently required for many applications, and the widespread use of exhaust particulate filters to achieve them, have resulted in the need to measure very low PM sample filter masses. This document describes particulate filter weigh-room recommended practices to provide guidance in the procedures and processes associated with gravimetric filter weighing of engine or vehicle particulate matter emissions. This recommended practice provides proper procedures to build and maintain a particulate filter weigh room or enclosure to meet the requirements of EPA's 40 CFR Part 1065 and ISO 14065 for obtaining low measurement uncertainty.