[Code of Federal Regulations]
[Title 40, Volume 31]
[Revised as of July 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR1065.201]

[Page 700]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 1065_ENGINE-TESTING PROCEDURES--Table of Contents
 
                    Subpart C_Measurement Instruments
 
Sec.  1065.201  Overview and general provisions.


    (a) Scope. This subpart specifies measurement instruments and 
associated system requirements related to emission testing in a 
laboratory and in the field. This includes laboratory instruments and 
portable emission measurement systems (PEMS) for measuring engine 
parameters, ambient conditions, flow-related parameters, and emission 
concentrations.
    (b) Instrument types. You may use any of the specified instruments 
as described in this subpart to perform emission tests. If you want to 
use one of these instruments in a way that is not specified in this 
subpart, or if you want to use a different instrument, you must first 
get us to approve your alternate procedure under Sec.  1065.10. Where we 
specify more than one instrument for a particular measurement, we may 
identify which instrument serves as the reference for showing that an 
alternative procedure is equivalent to the specified procedure.
    (c) Measurement systems. Assemble a system of measurement 
instruments that allows you to show that your engines comply with the 
applicable emission standards, using good engineering judgment. When 
selecting instruments, consider how conditions such as vibration, 
temperature, pressure, humidity, viscosity, specific heat, and exhaust 
composition (including trace concentrations) may affect instrument 
compatibility and performance.
    (d) Redundant systems. For all measurement instruments described in 
this subpart, you may use data from multiple instruments to calculate 
test results for a single test. If you use redundant systems, use good 
engineering judgment to use multiple measured values in calculations or 
to disregard individual measurements. Note that you must keep your 
results from all measurements, as described in Sec.  1065.25. This 
requirements applies whether or not you actually use the measurements in 
your calculations.
    (e) Range. You may use an instrument's response above 100% of its 
operating range if this does not affect your ability to show that your 
engines comply with the applicable emission standards. Note that we 
require additional testing and reporting if an analyzer responds above 
100% of its range. See Sec.  1065.550. Auto-ranging analyzers do not 
require additional testing or reporting.
    (f) Related subparts for laboratory testing. Subpart D of this part 
describes how to evaluate the performance of the measurement instruments 
in this subpart. In general, if an instrument is specified in a specific 
section of this subpart, its calibration and verifications are typically 
specified in a similarly numbered section in subpart D of this part. For 
example, Sec.  1065.290 gives instrument specifications for PM balances 
and Sec.  1065.390 describes the corresponding calibrations and 
verifications. Note that some instruments also have other requirements 
in other sections of subpart D of this part. Subpart B of this part 
identifies specifications for other types of equipment, and subpart H of 
this part specifies engine fluids and analytical gases.
    (g) Field testing and testing with PEMS. Subpart J of this part 
describes how to use these and other measurement instruments for field 
testing and other PEMS testing.