[Code of Federal Regulations]

[Title 40, Volume 31]

[Revised as of July 1, 2006]

From the U.S. Government Printing Office via GPO Access

[CITE: 40CFR1065.210]



[Page 701-704]

 

                   TITLE 40--PROTECTION OF ENVIRONMENT

 

         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)

 

PART 1065_ENGINE-TESTING PROCEDURES--Table of Contents

 

                    Subpart C_Measurement Instruments

 

Sec.  1065.210  Work input and output sensors.



    (a) Application. Use instruments as specified in this section to 

measure work inputs and outputs during engine operation. We recommend 

that you use sensors, transducers, and meters that meet the 

specifications in Table 1 of Sec.  1065.205. Note that your overall 

systems for measuring work inputs and outputs must meet the linearity 

verifications in Sec.  1065.307. We recommend that you measure work 

inputs and outputs where they cross the system boundary as shown in 

Figure 1 of this section. The system boundary is different for air-

cooled engines than for liquid-cooled engines. If you choose to measure 

work before or after a work conversion, relative to the system boundary, 

use good engineering judgment to estimate any work-conversion



[[Page 702]]



losses in a way that avoids overestimation of total work. For example, 

if it is impractical to instrument the shaft of an exhaust turbine 

generating electrical work, you may decide to measure its converted 

electrical work. In this case, divide the electrical work by an accurate 

value of electrical generator efficiency ([eta]<1), or assume an 

efficiency of 1 ([eta]=1), which would over-estimate brake-specific 

emissions. Do not underestimate the generator's efficiency because this 

would result in an under-estimation of brake-specific emissions. In all 

cases, ensure that you are able to accurately demonstrate compliance 

with the applicable standards.



[[Page 703]]



[GRAPHIC] [TIFF OMITTED] TR13JY05.015



    (b) Shaft work. Use speed and torque transducer outputs to calculate 

total work according to Sec.  1065.650.

    (1) Speed. Use a magnetic or optical shaft-position detector with a 

resolution of at least 60 counts per revolution, in combination with a 

frequency



[[Page 704]]



counter that rejects common-mode noise.

    (2) Torque. You may use a variety of methods to determine engine 

torque. As needed, and based on good engineering judgment, compensate 

for torque induced by the inertia of accelerating and decelerating 

components connected to the flywheel, such as the drive shaft and 

dynamometer rotor. Use any of the following methods to determine engine 

torque:

    (i) Measure torque by mounting a strain gage or similar instrument 

in-line between the engine and dynamometer.

    (ii) Measure torque by mounting a strain gage or similar instrument 

on a lever arm connected to the dynamometer housing.

    (iii) Calculate torque from internal dynamometer signals, such as 

armature current, as long as you calibrate this measurement as described 

in Sec.  1065.310.

    (c) Electrical work. Use a watt-hour meter output to calculate total 

work according to Sec.  1065.650. Use a watt-hour meter that outputs 

active power (kW). Watt-hour meters typically combine a Wheatstone 

bridge voltmeter and a Hall-effect clamp-on ammeter into a single 

microprocessor-based instrument that analyzes and outputs several 

parameters, such as alternating or direct current voltage (V), current 

(A), power factor (pf), apparent power (VA), reactive power (VAR), and 

active power (W).

    (d) Pump, compressor or turbine work. Use pressure transducer and 

flow-meter outputs to calculate total work according to Sec.  1065.650. 

For flow meters, see Sec.  1065.220 through Sec.  1065.248.