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frared analyzers are turned off and the period, representing the “stabilized” phototube high voltage supply of the phase, consists of the remainder of the chemiluminescence analyzer is placed in driving schedule including engine shutthe standby position.) The following se down. The hot start test similarly conquence of operations should be per sists of two periods. The first period, formed in conjunction with each series representing the hot start “transient" of measurements:

phase, terminates at the same point in (1) Zero the analyzers. Obtain a stable the driving schedule as the first phase zero on each amplifier meter and re- of the cold start test. The second period corder. Recheck after tests.

of the hot start test, "stabilized” phase, (2) Introduce span gases and set the is assumed to be identical to the second CO and CO, analyzer gains, the HC ana period of the cold start test. Therefore, lyzer sample capillary flow rate and the the hot start test terminates after the NO, analyzer high voltage supply or am- first period (505 seconds) is run. During plifier gain to match the calibration the tests the ambient temperature shall curves. In order to avoid corrections, be between 68° F. and 86° F. span and calibrate at the same flow rates (b) The following steps shall be taken used to analyze the test samples. Span for each test: gases should have concentrations equal (1) Place drive wheels of vehicle on to approximately 80 percent of full scale. dynamometer without starting engine, If gain has shifted significantly on the (2) Open the vehicle engine compartCO or CO, analyzers, check tuning. If ment cover and start the cooling fan. necessary, check calibration. Recheck (3) With the sample solenoid valves in after test. Show actual concentrations the “dump" position connect evacuated on chart.

sample collection bags to the two dilute (3) Check zeroes; repeat the proce exhaust sample connectors and to the dure in subparagraphs (1) and (2) of two dilution air sample line connectors. this paragraph if required.

(4) Start the positive displacement (4) Check flow rates and pressures. pump (if not already on), the sample

(5) Measure HC, CO, CO2, and NO, pumps, and the temperature recorder. concentrations of samples. Care should (The heat exchanger of the constant vol. be exercised to prevent moisture from ume sampler should be preheated to its condensing in the sample collection bag operating temperature before the test (6) Check zero and span points.

begins.) (c) For the purposes of this section, (5) Adjust the sample flow rates to the term "zero grade air" includes arti the desired flow rate (minimum of 10 ficial "air" consisting of a blend or nitro c.f.h.) and set the revolution counters gen and oxygen with oxygen concentra- to zero. tions between 18 and 21 mole percent. (6) Attach the flexible exhaust tube to 8 85.075-24

the vehicle tailpipe(s). Dynamometer test runs.

(7) Simultaneously start the revolu(a) The vehicle shall be allowed to tion counter for the positive displacestand with the engine turned off for a ment pump, position the sample solenoid period of not less than 12 hours before valves to direct the sample flow into the the cold start exhaust emission test, at "transient" exhaust sample bag and the an ambient temperature as specified in "transient" dilution air sample bag, and $8 85.075-12 and 85.075-13. The vehicle start cranking the engine. shall be stored prior to the emission tests (8) Fifteen seconds after the engine in such a manner that precipitation (e.g. starts, place the transmission in gear. rain or dew) does not occur on the ve (9) Twenty seconds after the engine hicle. The complete dynamometer test starts, begin the initial vehicle acceleraconsists of a cold start drive of 7.5 miles tion of the driving schedule. and simulates a hot start drive of 7.5 (10) Operate the vehicle according to miles. The vehicle is allowed to stand on the dynamometer driving schedule the dynamometer during the 10-minute ($ 85.075-14). time period between the cold and hot (11) At the end of the deceleration start tests. The cold start test is divided which is scheduled to occur at 505 secinto two periods. The first period, repre onds, simultaneously switch the sample senting the cold start “transient” phase, flows from the "transient” bags to the terminates at the end of the deceleration "stabilized" bags, switch off revolution which is scheduled to occur at 505 sec- counter No. 1 and start counter No. 2. onds of the driving schedule. The second As soon as possible and in no case longer

than 20 minutes after the end of this and dilute exhaust sample bags from the portion of the test disconnect the "tran- instrument deflections or recordings sient” exhaust and dilution air sample making use of appropriate calibration bags, transfer them to the analytical sys charts. tem and process the samples according (b) Determine the average dilute exto $ 85.075-23.

haust mixture temperatures from the (12) Turn the engine off 2 second after temperature recorder trace if a recorder the end of the last deceleration (at 1,369 is used. seconds).

(13) Five seconds after the engine stops & 85.075-26 Calculations (exhaust emis. running, simultaneously turn off revolu

sions). tion counter No. 2 and position the sam

The final reported test results shall be ple solenoid valves to the "dump” posi

computed by use of the following tion. As soon as possible and in no case

formulae: longer than 20 minutes after the end of this portion of the test disconnect the

(a) For light duty vehicles: “stabilized” exhaust and dilution air

Yum=(0.43 Yc+0.57 Yurt Y.)/7.5 sample bags, transfer them to the ana where: lytical system and process the samples Yum=Weighted mass emissions of each pollutant, 1.e. according to $ 85.075-23.

HC, CO, or NO,, in grams per vehicle mile.

Y., Mass emissions as calculated from the "tran(14) Immediately after the end of the

sient” phase of the cold start test, in grams sample period turn off the cooling fan

per test phase.

Y Mass emissions as calculated from the "tranand close the engine compartment cover.

sient" phase of the hot start test, in grams (15) Immediately after the end of the

per test phase. sample period, disconnect the exhaust

Y.-Mass emissions as calculated from the "stabt

lized" phase of the cold start test, 3in grams tube from the tailpipe(s), turn off the

per test phase. cooling fan and close the engine com (b) The mass of each pollutant for partment cover.

each phase of both the cold start test and (16) Turn off the positive displacement the hot start test is determined from the pump.

following: (17) Repeat the steps in subpara (1) Hydrocarbon Mass: graphs (2) through (10) of this paragraph for the hot start test except only

HCM...V mieX DensityacX1000.000 one evacuated sample bag is required for sampling exhaust gas and one for dilu (2) Oxides of nitrogen Mass: tion air. The step in subparagraph (7) of this paragraph shall begin between 9 and NOsmo..=VmisXDensityno,

X X K

1,000,000 11 minutes after the end of the sample period for the cold start test.

(3) Carbon monoxide Mass: (18) At the end of the deceleration

COman=VmizXDensitycoX which is scheduled to occur at 505 sec

1,000,000 onds, simultaneously turn off the No. 1

(c) Meaning of symbols: revolution counter and position the sample solenoid valve to the "dump" posi HCme=Hydrocarbon emissions, in grams per test

phase. tion. (Engine shutdown is not part of the Densityc=Density of hydrocarbons in the exhaust gas, hot start test sample period.)

assuming an average carbon to hydrogen

ratio of 1:1.85, in grams per cubic foot at (19) As soon as possible and in no case

68° F. and 760 mm. Hg pressure (16.33 longer than 20 minutes after the end of

gm./cu. ft.). this portion of the test disconnect the

HC conHydrocarbon concentration of the diluto

exhaust sample corrected for background, hot start “transient" exhaust and dilu

in p.p.m. carbon equivalent. i.e. equiytion air sample bags, transfer them to the

alent propane X3. analytical system and process the sam

HCcone=HC.-HC4(1-1/DF)

where: ples according to $ 85.075-23.

HC.-Hydrocarbon concentrations of the diluto (20) Disconnect the exhaust tube from

exhaust sample as measured, in p.p.m. the vehicle tailpipe(s) and remove ve

carbon equivalent.

HC-Hydrocarbon concentration of the dilution hicle from dynamometer.

air as measured in p.p.m. carbon equiva(21) The positive displacement pump

lent. may be turned off, if desired.

NO: man-Oxides of nitrogen emissions, in grams per,

test phase. Amenitrogen in the exhaust 8 85.075_25 Chart reading.

Density Nor=Density of oxi

gas, assuming they are in the form of (a) Determine the HC, CO, CO, and

nitrogen dioxide, in grams per cubic foot

at 68° F. and 760 mm. Hg pressure NO, concentrations of the dilution air

(54.16 gm./cu. ft.).

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CO come

N 01 cone=Oxides of nitrogen concentration of the

dilute exhaust sample corrected for back

ground, in p.p.m. NOrcone-N0..-N0.,(1--1/DF)

Vmir=Total dilute exhaust volume in cubic feet per

test phase corrected to standard conditions (528.R and 760 mm. Hg).

(PB-P:) (528, R) V mis–V.XN

(760 mm. Hg) (T) where: Vo=Volume of gas pumped by the positive displace

ment pump, in cubic feet per revolution. This volume is dependent on the pressure differential

across the positive displacement pump. N=Number of revolutions of the positive displare

ment pump during the test phase while samples

are being collected PB=Barometric pressure in mm. Hg. Pi-Pressure depression below atmosphere measured

at the inlet to the positive displacement pump. T,=Average temperature of dilute exhaust entering

positive displacement pump during test while

samples are being collected, in degrees Rankine. Ky=Humidity correction factor.

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where:
NO,,=Oxides of nitrogen concentration of the

dilute exhaust sample as measured, in

p.p.m. N02,=Oxides of nitrogen concentration of the

dilution air as measured, in p.p.m. COman.Carbon monoxide emissions, in grams per

test phase. Densityco=Density of carbon monoxide in grams per

cubic foot at 68° F. and 760 mm. Hg

pressure (32.97 gm./cu. ft.).
COco e=Carbon monoxide concentration of the

dilute exhaust sample corrected for back-
ground, water vapor and CO2 extraction,

in p.p.m.
COcone=C0,-CO(1-1/DF)
where:
CO.Carbon monoxide concentration of the dilute

exhaust sample volume corrected for water.
vapor and carbon dioxide extraction, in p.p.m
The calculation assumes the carbon to hy.

drogen ratio of the fuel is 1:185.
C0,=(1-0.01925C ON-0.000323R) CO..
where:
COor=Carbon monoxide concentration of the dilute

exhaust sample as measured in p.p.m. CO2.=Carbon dioxide concentration of the dilute

exhaust sample, in mole percent. R=Relative humidity of the dilution air, in

percent. CO=Carbon monoxide concentration of the dilution

air corrected for water vapor extraction, in

p.p.m. COs=(10.000323R)CO.m where: COdm=Carbon monoxide concentration of the dilution air sample as measured, in p.p.m.

13.4 DF=

CO2+(HC.+00.)X104

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& 85.075-27 Calculations (fuel evapora. cept the zero mile tests. This shall tive emissions).

include the oficial test results, as deterThe net weights of the individual col

mined in $ 85.075-29, for all tests conlection traps employed in $ 85.075-13

ducted on all durability vehicles of the shall be added together to determine

combination selected under $ 85.075-5 compliance with the fuel evaporative

(c) (including all vehicles elected to be emission standard.

operated by the manufacturer under

$ 85.075-5 (c) (3)). 8 85.075–28 Compliance with emission (6) All emission data from the tests standards.

conducted before and after the scheduled (a) The exhaust and fuel evapora maintenance provided in $$ 85.075-6(a) tive emission standards in $ 85.075-1 (1) (i), (1) (iii), (3), (4), and (5) (iii). apply to the emissions of vehicles for

(c) All emission data from tests retheir useful life.

quired by maintenance approved under (b) Since emission control efficiency

$ 85.075-6(a) (1) (ix), in those cases decreases with mileage accumulated on

where the Administrator conditioned the vehicle, the emission level of a ve his approval for the performance of hicle which has accumulated 50,000 such maintenance on the inclusion of miles will be used as the basis for such data in the deterioration factor determining compliance with the calculation. standards.

(ii) All applicable results shall be (c) The procedure for determining plotted as a function of the mileage on compliance of a new light duty motor the system, rounded to the nearest mile, vehicle with exhaust and fuel evaporative

and the best fit straight lines, fitted by emission standards is as follows:

the method of least squares, shall be (1) Separate emission deterioration drawn through all these data points. The factors shall be determined from the interpolated 4,000- and 50,000-mile emission results of the durability vehi

points on this line must be within the cle for each engine-system combina

standards provided in $ 85.075–1 or the tion. A separate factor shall be estab

data will not be acceptable for use in callished for exhaust HC, exhaust CO, ex

culation of a deterioration factor, unless haust NOx, and fuel evaporative HC.

no applicable data point exceeded the (i) The applicable results to be used in determining the deterioration factors

standard. for each combination shall be:

(iii) An exhaust emission deteriora(a) All valid emission data from the tion factor shall be calculated for each tests required under $ 85.075–7(b), ex- combination as follows:

exhaust emissions interpolated to 50,000 miles factor=

exhaust emissions Interpolated to 4,000 miles These interpolated values shall be car- polated values shall be carried out, in ried out to a minimum of four places accordance with ASTM E 29-67, to a to the right of the decimal point before minimum of three decimal places to the dividing one by the other to determine right of the decimal point before subthe deterioration factor. The results shall tracting one from the other to determine be rounded to three places to the right the deterioration factor. of the decimal point in accordance with (2) (i) The exhaust emission test reASTM E 29–67.

sults for each emission data vehicle shall (iv) An evaporative emission deterio- be multiplied by the appropriate deterioration factor shall be calculated for each ration factor: Provided, That if a decombination by subtracting the evap- terioration factor as computed in paraorative emissions interpolated to 4,000 graph (c) (1) (iii) is less than one, that miles from the evaporative emissions in- deterioration factor shall be one for the terpolated to 50,000 miles. These inter- purposes of this paragraph.

(ii) The evaporative emission test re- lack of correlation are determined and sults for each combination shall be ad- the validity of the data is established by justed by addition of the appropriate the manufacturer. deterioration factor: Provided, That if a (3) (i) The emission data vehicle predeterioration factor as computed in par sented to the Administrator for testing agraph (3) (1) (iv) is less than zero, that shall be calibrated within the production deterioration factor shall be zero for the tolerances applicable to the manufacpurposes of this paragraph.

turer's specifications to be shown on the (3) The emissions to compare with vehicle label (see $ 85.075–35(a) (4) (iv)) the standard shall be the adjusted emis as specified in the application for cersions of paragraph (c) (2) (i) and (ii) tification. If the Administrator deterfor each emission data vehicle. Before mines that a vehicle is not within such any emission value is compared with the tolerances, the vehicle shall be adjusted standard, it shall be rounded, in accord at the facility designated by the Adminance with ASTM E 29–67, to two sig istrator prior to the test and an enginificant figures. The rounded emission neering report shall be submitted to the values may not exceed the standard. Administrator describing the corrective

(4) Every test vehicle of an engine action taken. Based on the engineering family must comply with all applicable report, the Administrator will determine standards, as determined in paragraph if the vehicle shall be used as an emis(c)(3), before any vehicle in that family sion data vehicle. may be certified.

(ii) If the Administrator determines

that the test data developed under para& 85.075-29 Testing by the Administra

graph (b) (3) (i) would cause the emistor.

sion data vehicle to fail due to excessive (a) The Administrator may require 4,000 mile emissions or by application that any one or more of the test vehicles of the appropriate deterioration factor, be submitted to him, at such place or then the following procedure shall be places as he may designate, for the pur observed: pose of conducting emissions tests. The (a) The manufacturer may request a Administrator may specify that he will retest. Before the retest, the vehicle may conduct such testing at the manufac be readjusted to manufacturer's specifiturer's facility, in which case instrumen cations, if these adjustments were made tation and equipment specified by the incorrectly prior to the first test, and Administrator shall be made available by other maintenance or repairs may be the manufacturer for test operations. performed in accordance with $ 85.075-6. Any testing conducted at a manufac All work on the vehicle shall be done at turer's facility pursuant to this para such location and under such conditions graph shall be scheduled by the manu as the Administrator may prescribe. facturer as promptly as possible.

(b) The vehicle will be retested by the (b) (1) Whenever the Administrator Administrator and the results of this conducts a test on a test vehicle, the re- test shall comprise the official data for sults of that test, unless subsequently the emission data vehicle. invalidated by the Administrator, shall (4) If suficient durability data are not comprise the official data for the vehicle available at the time of any emission test at that prescribed test point and the conducted under paragraph (a) of this manufacturer's data for that prescribed section, to enable the Administrator to test point shall not be used in determin determine whether an emission data veing compliance with emission standards. hicle would fail, the manufacturer may

(2) Whenever the Administrator does request a retest in accordance with the not conduct a test on a test vehicle at a provisions of paragraphs (C) (3) (i) (a) test point, the manufacturer's test data and (b) of this paragraph. If the manuwill be accepted as the official data for facturer does not promptly make such that test point: Provided, That if the request, he shall be deemed to have Administrator makes a determination waived the right to a retest. A request based on testing under paragraph (a) of for retest must be made before the manthis section, that there is a lack of cor- ufacturer removes the vehicle from the relation between the manufacturer's test

test premises. equipment and the test equipment used by the Administrator; no manufacturer's

$ 85.075-30 Certification. test data will be accepted for purposes of (a) (1) If, after a review of the test certification until the reasons for the reports and data submitted by the manu

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