Measurement of vehicle particulate emissions.

Abstract

A constant volume sampler (CVS) compatible auto exhaust particulate sampling system has been built which samples exhaust isokinetically at constant temperature. This system yields internally consistent results and is capable of frequent and convenient operation.

Real-Time, Continuous Measurement of Automotive Sulfuric Acid Emissions

“…4 ' 12 This system allows diluted auto exhaust to develop a uniforrii velocity profile prior to isokinetic sampling and collecting exhaust particulate by filtering a portion of the sample stream using a variety of filters. Filtration is carried out at a constant temperature of 32°C.…”

“…Sulfur dioxide could interfere if it existed as bisulfite ion in the aerosol. This is not likely, as the H2SO4 aerosol is about 40 wt % sulfuric acid, 4 ' 5 corresponding to a 4 molar solution (pH <0). Based on an extrapolation of the SO2 solubility-pH data of Hales and Sutter, 7 the dissolved SO2 concentration assuming 5 ppm of SO2 in the diluted exhaust sample stream would be only 6.8 X 10~6 molar.…”

Emission Control Devices, Fuel Additive, and Fuel Composition Changes

“…Since that time, Beltzer et al (9) and Somers (10) A series of eight 10.5 m sampling towers were situated in the north-south aligned test tract so that one tower was located in the median strip, five were on the east side of the tract, and two were on the west side of the tract. On the west side, the towers were located 2 and 30 m from the edge of the highway, and on the east side of the tract, the towers were located 4, 15, 30, 50, and 100 m from the edge of the highway.…”

Method for determining H2SO4 in automobile exhaust.

“…A modification of the Federal Testing Procedure for H2SO4 and sulfur dioxide from stationary sources has been used by a division of the Environmental Protection Agency (EPA). Esso (1) and Ford (2) reported on data obtained by using dilution tubes together with filter systems for collecting exhaust particulates with subsequent analysis of the particulate for sulfate. This paper describes a method being developed by Chevron Research for sampling and analyzing auto exhaust for sulfate.…”