Accession Number : ADD003082
Title : Sampling and Dilution Method.
Descriptive Note : Patent,
Corporate Author : DEPARTMENT OF THE ARMY WASHINGTON D C
Personal Author(s) : Hadden,Stephen C ; Hulls,Leonard R
Report Date : 29 Jun 1976
Pagination or Media Count : 4
Abstract : The patent discusses a conduit arrangement for measuring unburned combustibles in the exhaust stream issuing from an engine. A restriction is provided in the exhaust duct to form a superatmospheric pressure zone upstream from the restriction and a subatmospheric pressure zone downstream from the restriction. A minor fraction of the exhaust gas is bypassed around the restriction through a conduit system communicating with the two above-mentioned zones. A sampling chamber containing a combustibles sensor is located in the conduit system. An auxiliary conduit communicates the interior of the sampling chamber with the ambient atmosphere so that cooling air is drawn into the chamber to dilute the sampled gas. The dilution air lowers the temperature of the gas-air mixture, thereby cooling the sensor against heat degradation by the otherwise undiluted gas. The dilution air also contributes oxygen to the gas stream, thereby enhancing catalytic oxidation processes on which certain sensors depend for response to combustibles (CO and CH).
Descriptors : *Patents, *Samplers, *Exhaust gases, Sampling, Carbon monoxide, Hydrocarbons, Electrochemistry, Performance tests, Dilution, Measuring instruments, Coolants, Particulates
Subject Categories : Physical Chemistry
Test Facilities, Equipment and Methods
Distribution Statement : APPROVED FOR PUBLIC RELEASE