SAE ARP6320B

This ARP describes recommended sampling conditions, instrumentation, and procedures for the measurement of nonvolatile particle number and mass concentrations from the exhaust of aircraft gas turbine engines. Procedures are included to estimate sampling system loss performance. This ARP is not intended for in-flight testing, nor does it apply to engines operating in the afterburning mode. This ARP is intended as a guide toward standard practice and is subject to change to keep pace with experience and technical advances. This SAE Aerospace Recommended Practice (ARP) revision provides updates to the system particle loss, sampling probe, system cleanliness, and nonvolatile particulate matter (nvPM) instrument requirements sections. Minor clarifications or editorial changes throughout document are also included. This revision is limited in scope. a System Particle Loss: An updated definition of the T1 location from Diluter1 inlet to Splitter1 metal. This ARP revision (as well as the latest revision to ARP6481) implements an additional Section 2 thermophoretic loss for system loss factor calculation (which also accounts for Diluter1 penetration). The Section 2 thermophoretic loss is expected to be an interim revision while further work is performed to verify Section 2 particle loss and improve uncertainty. To help this work, this ARP has been revised to include reporting of additional Section 2 measured sampling system temperatures near the Diluter1 inlet that are measured in some specific system designs. b System Cleanliness: Improved cyclone cleanliness wording to help system user operability. c nvPM Instrument Requirements: Added clarifications on nvPM instruments for end users to maintain documentation of performance specifications, a flow chart highlighting specific steps required before measuring nvPM mass emissions from an aircraft engine, and requirements for calibration DFCAS. d Probe: Added clarity that the pressure drop requirement is for multi-hole probes only.