[Code of Federal Regulations]
[Title 40, Volume 18]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR91.304]

[Page 318]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 91--CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES--Table of 
Contents
 
              Subpart D--Emission Test Equipment Provisions
 
Sec. 91.304  Test equipment overview.

    (a) All engines subject to this subpart are tested for exhaust 
emissions. Engines are operated on dynamometers meeting the 
specification given in Sec. 91.305.
    (b) The exhaust is tested for gaseous emissions using either a 
constant volume sampling (CVS) system as described in Sec. 91.414, or 
using the raw gas sampling system as described in Sec. 91.421. Both 
systems require analyzers (see paragraph (c) of this section) specific 
to the pollutant being measured.
    (c) Analyzers used are a non-dispersive infrared detector (NDIR) 
absorption type for carbon monoxide and carbon dioxide analysis; 
paramagnetic detector (PMD), zirconia (ZRDO), or electrochemical type 
(ECS) for oxygen analysis; a flame ionization detector (FID) or heated 
flame ionization detector (HFID) type for hydrocarbon analysis; and a 
chemiluminescent detector (CLD) or heated chemiluminescent detector 
(HCLD) for oxides of nitrogen analysis.