1

The Result of Japan’sRound Robin Engine Test:

Measurement of PM and PN

3/30/2009PMP Informal Meeting

National Traffic Safety and Environmental LaboratoryJapan Automobile Research Institute

2

Contents

Outline and Objective Round Robin Test Results Understanding the Factors Affecting the

Measurement Results Summary

3

Outline and Objective

Japan’s round robin test, the measurement of PN and PM using HD engines, was conducted at two laboratories (NTSEL and JARI).

The round robin test in Japan had the following two objectives: To perform testing according to Validation Exercise at

NTSEL and JARI and supply data to PMP; To study the optimum measurement method as the PN-

measurement method and filter-weight method and provide data that will help determine the measurement procedures.

4

Specifications of Test Engine and Fuel

Engine Model HINO J08E-TP

Configuration Inline 6cyl, w/I.C.,T.C.

Bore X Stroke 112 X 130

Displacement 7.684 L

Compression ratio 18.0

Injection System Common Rail (Max 1600bar)

Emission Reduction Device DPF w/Cat., Cooled EGR

Performance 177kW / 2700rpm

Emission 2005JP, nearly EURO V

Test Engine

Test Fuel

In conformity with RF-06-03

5

Specifications of Full and Partial Tunnels

NTSEL(Lab. A)

JARI(Lab. B)

Full Tunnel

1st Tunnel Diameter 457 mm 605 mm

CVS Flow 50 m3/min 60 m3/min

2nd Tunnel Diameter 83 mm 83 mm

PM Sample Flow Rate 67 L/min 68 L/min

Dilution Air Flow Rate 50 L/min 15 L/min

Partial　Tunnel

Tunnel Diameter 29.4 mm 29.4 mm

PM Sample Flow Rate 67 L/min 68 L/min

Split Ratio of Exhaust Flow 1/700 1/1000

PM Sample

Filter Material TX47Φ TX47Φ

Temperature 475C 475C

6

Particle Number Counting System 2 Horiba systems and 1 Matter system were used. One of the

Horiba systems was used by both laboratories as common system.

System Maker Model No.PND1

dilution ratio setting

PND2dilution

ratio settingTested by

SPCS1 Horiba MEXA-1000SPCS 10 15NTSEL (Full)

JARI (Full/Partial)

SPCS2 Horiba MEXA-1000SPCS 20 15 NTSEL (Partial)

Matter Matter MD19+ASET15 22 10 JARI (Full/Partial)

NTSEL

Conducted simultaneous measurement with full and partial tunnels in the same test using 2 SPCSs.

JARI

Conducted measurement at the same sampling point using 1 SPCS and 1 Matter. Measurement with full tunnel and that with partial tunnel were performed in separate tests.

0.90

0.95

1.00

1.05

1.10

1.15

1.20

1.25

1.30

1.35

1.40

0 20 40 60 80 100 120

Dp (nm)

Fr

(Dp

) / F

r(1

00

nm

) (-

)

SPCS1 SPCS2 Matter Upper Limit Lower Limit

PNCS Data to Calculate Emission

No problem with PNC provisions (cut-off point, correlation with reference meter).

As to PCRF, all systems were within the specified range; however, Fr(50nm)/Fr(100nm) ratio was below 1 in one system. Possibly problematic.

0.0

0.2

0.4

0.6

0.8

1.0

1.2

10 100

Mobility diameter (nm)

Co

un

ting

effi

cie

ncy

(-)

SPCS1 (Lab. A-Full & Lab. B) SPCS2 (Lab. A-Partial) Matter

SPCS1: y = 0.9313x

SPCS2: y = 0.9559 x

Matter: y = 0.9189x

0.0E+00

2.0E+03

4.0E+03

6.0E+03

8.0E+03

1.0E+04

1.2E+04

0.0E+00 2.0E+03 4.0E+03 6.0E+03 8.0E+03 1.0E+04 1.2E+04

PN conc. with AIST electrometer (#/cm3)

PN

co

nc. w

ith P

NC

(#

/cm3 )

SPCS1 (Lab. A-Full & Lab. B) SPCS2 (Lab. A-Partial) Matter

PNC cut-off point Linearity check against electrometer

PCRF regulation

7

8

Daily Schedule of the Round Robin TestMon. Tue. - Fri. Remarks

0 Each lab’s own test for study

IFV

1 BG

2 C_WHTC#1~8

3 10 min soak

4 H_WHTC#1~8

5 CP

6 WHSC#1~8

7 Rated 20 min. Rated 20 min.

8 Engine stop 10 min.

Engine stop 10 min.

9 Preliminary JE05 Preliminary JE05

10 Engine stop 10 min.

Engine stop 10 min.

11 Full JE05 test Full JE05 test

12 15 min.

13 BG

IFV: Instrument Functional Verification (Daily check of PNCS, etc.)CP: Continuous Protocol (Idle 6 min. WHSC mode9 10 min. Engine stop 5 min.)PC: Power Curve (Not to be recorded; To be checked at rated operation before JE05 test; rated output only)SMP: Stabilization Mode Protocol (JE05 test to be defined as SMP)

Tunnel blank (TB) measurement:

Sampling time: 30 min.Measurement timing: At start and completion of daily test

9

Contents

Outline and Objective Round Robin Test Results Understanding the Factors Affecting the

Measurement Results Summary

0.0

0.4

0.8

1.2

1.6

2.0

WHTCCold

WHTCHot

WHSC JE05

CO

em

issi

on

(g

/kW

h)

Lab. A

Lab. B-Full

Lab. B-Partial

Error bar: ±σ

0

100

200

300

400

500

600

700

800

900

1000

WHTCCold

WHTCHot

WHSC JE05

CO

2 e

mis

sio

n (

g/k

Wh

)

Lab. A

Lab. B-Full

Lab. B-Partial

Error bar: ±σ

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

WHTCCold

WHTCHot

WHSC JE05

TH

C o

r N

MH

C e

mis

sio

n (

g/k

Wh

)

Lab. A

Lab. B-Full

Lab. B-Partial

Error bar: ±σ

0.0

0.5

1.0

1.5

2.0

2.5

3.0

WHTCCold

WHTCHot

WHSC JE05

NO

x e

mis

sio

n (

g/k

Wh

)

Lab. A

Lab. B-Full

Lab. B-Partial

Error bar: ±σ

10

Gaseous Emission

* CO & HC: Slight differences in the result among labs in some modes; good repeatability.* NOx & CO2: Almost the same results among labs; good repeatability.

0.000

0.002

0.004

0.006

0.008

0.010

WHTCCold

WHTCHot

WHSC JE05

PM

em

issi

on

with

ou

t TB

co

rre

ctio

n (

g/k

Wh

)

Mean(All-Data)Lab. A

Lab. B

Error bar: ±σ

0.000

0.002

0.004

0.006

0.008

0.010

WHTCCold

WHTCHot

WHSC JE05

PM

em

issi

on

with

TB

co

rre

ctio

n (

g/k

Wh

)

Mean(All-Data)Lab. A

Lab. B

Error bar: ±σ

0.000

0.002

0.004

0.006

0.008

0.010

WHTCCold

WHTCHot

WHSC JE05

PM

em

issi

on

with

ou

t TB

co

rre

ctio

n (

g/k

Wh

)

Mean(All-Data)Lab. A

Lab. B

Error bar: ±σ

0.000

0.002

0.004

0.006

0.008

0.010

WHTCCold

WHTCHot

WHSC JE05

PM

em

issi

on

with

ou

t TB

co

rre

ctio

n (

g/kW

h)

Mean(All-Data)Lab. A

Lab. B

Error bar: ±σ

11

PM EmissionWithout tunnel blank correction With tunnel blank correction

Before TB correction, emission levels of Lab. A were significantly higher than the others; After TB correction, emission levels of Lab. A and Lab. B became almost the same.

PM emission: JE05 > WHTC-Hot WHTC-Cold WHSC

Full tunnel

Partial tunnel

Without tunnel blank correction

Full tunnel

With tunnel blank correction

Partial tunnel

1.0E+09

1.0E+10

1.0E+11

1.0E+12

WHTCCold

WHTCHot

WHSC JE05

PN

em

issi

on

(#

/kW

h) Mean

(All-Data)Lab. A-SPCS1

Lab. B-SPCS1

Error bar: ±σ

12

PN (Number) Emission -Full Tunnel-

Full tunnel:

* The emission levels in WHTC-C/H of Lab. A and Lab. B were almost the same.

* The emission level in WHSC of Lab. A and that in JE05 of Lab. B were about 3 times higher, respectively.

　 Also, even when the same PNCS was used, the result differed between labs.

1.0E+09

1.0E+10

1.0E+11

1.0E+12

WHTCCold

WHTCHot

WHSC JE05

PN

em

issi

on

(#

/kW

h)

Mean(All-Data)

Lab. A-SPCS1

Lab. B-Matter

Error bar: ±σ

Inter-Lab test Round-Robin test

13

PN (Number) Emission -Partial Tunnel-

Partial tunnel:

* The emission levels of Lab. A and Lab. B were the same as the full tunnel, except for JE05.

* The emission level in JE05 of Lab. B was about double the level in the full tunnel.

　 Also, even when the same-model PNCS was used, the result differed between labs.

PN emission: JE05 > WHTC-Cold > WHTC-Hot WHSCThe emission-level order of WHTC-Cold differed between PM and PN.

1.0E+09

1.0E+10

1.0E+11

1.0E+12

WHTCCold

WHTCHot

WHSC JE05

PN

em

issi

on

(#

/kW

h) Mean

(All-Data)Lab. A-SPCS2

Lab. B-Matter

Error bar: ±σ

1.0E+09

1.0E+10

1.0E+11

1.0E+12

WHTCCold

WHTCHot

WHSC JE05

PN

em

issi

on

(#

/kW

h) Mean

(All-Data)Lab. A-SPCS2

Lab. B-SPCS1

Error bar: ±σ

Round-Robin test Same model

14

Comparison of COV for PM

0

20

40

60

80

100

Full Partial Full Partial Full Partial Full Partial

Co

effi

cie

nt o

f Va

lida

tion

(%

)

Mean(All-Data)Lab. A

Lab. B

WHTC-Cold WHTC-Hot WHSC JE05

0

20

40

60

80

100

120

140

Full Partial Full Partial Full Partial Full Partial

Co

effi

cie

nt o

f Va

lida

tion

(%

)

Mean(All-Data)Lab. A

Lab. B

WHTC-Cold WHTC-Hot WHSC JE05

TB correction on PM lowered emission levels, causing COV to be higher.

However, TB correction reduced the standard deviation (g/kWh), resulting in smaller variations.

Without TB correction With TB correction

0.0000

0.0005

0.0010

0.0015

0.0020

0.0025

0.0030

Full Partial Full Partial Full Partial Full Partial

Sta

nd

ard

De

via

tion

(g

/kW

h)

Mean(All-Data)Lab. A

Lab. B

WHTC-Cold WHTC-Hot WHSC JE05

0.0000

0.0005

0.0010

0.0015

0.0020

0.0025

0.0030

Full Partial Full Partial Full Partial Full Partial

Sta

nd

ard

De

via

tion

(g

/kW

h)

Mean(All-Data)Lab. A

Lab. B

WHTC-Cold WHTC-Hot WHSC JE05

Without TB correction With TB correction

0

10

20

30

40

50

60

70

80

90

100

WHTCCold

WHTCHot

WHSC JE05

CO

V o

f PN

em

issi

on w

ith fu

ll tu

nn

el (

%)

Mean(All-Data)

Lab. A-SPCS1

Lab. B-Matter

0

10

20

30

40

50

60

70

80

90

100

WHTCCold

WHTCHot

WHSC JE05

CO

V o

f PN

em

issi

on w

ith fu

ll tu

nn

el (

%)

Mean(All-Data)

Lab. A-SPCS2

Lab. B-Matter

15

Comparison of COV for PN

COV for PN:* No large difference between full tunnel and micro tunnel dilutions; around the same level.* COV was 20%-70%; almost the same level as PM without TB correction.

Full tunnel

0

10

20

30

40

50

60

70

80

90

100

WHTCCold

WHTCHot

WHSC JE05

CO

V o

f PN

em

issi

on w

ith fu

ll tu

nn

el (

%)

Mean(All-Data)

Lab. A-SPCS1

Lab. B-SPCS1

0

10

20

30

40

50

60

70

80

90

100

WHTCCold

WHTCHot

WHSC JE05

CO

V o

f PN

em

issi

on w

ith fu

ll tu

nn

el (

%)

Mean(All-Data)

Lab. A-SPCS2

Lab. B-SPCS1

Full tunnel

Partial tunnel

Partial tunnel

RR test

IL test

Another type PNCS

Same type PNCS

PM Emission in ETC and ESC Modes

No unique tendency in the emission level and COV was observed in either ETC or ESC.

0.0000

0.0005

0.0010

0.0015

0.0020

0.0025

0.0030

WHTC

Cold

WHTC

Hot

WHSC

JE05

ETC ESC

PM

em

issi

on

(g

/kW

h)

Full

Partial

PMLab. A

0

20

40

60

80

100

120

140

WHTC

Cold

WHTC

Hot

WHSC

JE05

ETC ESC

CO

V o

f PM

em

issi

on

(%

) Full

Partial

PMLab. AEmission COV

16

0

20

40

60

80

100

120

140

160

WHTC

Cold

WHTC

Hot

WHSC

JE05

ETC ESC

CO

V o

f PN

em

issi

on

(%

) Full

Partial

PNLab. A

0.0E+00

5.0E+10

1.0E+11

1.5E+11

2.0E+11

2.5E+11

WHTC

Cold

WHTC

Hot

WHSC

JE05

ETC ESC

PN

em

issi

on

(#

/kW

h)

Full

Partial

PNLab. A

PN Emission in ETC and ESC Modes

Correlation of PN and PM was good in both ETC and ESC, similarly to WHTC Hot, etc.

COV were relatively high in ETC and ESC, which is presumed to have been caused by the conditions being not uniform due to the simple preconditioning procedures.

Emission COV

17

18

Effect of Tunnel Blank - Measured values -

Amount of PM trapped (mg/30min) Average PN (#/cc/30min)

PM:TB levels of PM were high with test of the partial tunnel of Lab. A.

PN:TB levels were higher with SPCS system than Matter system in this research.TB levels of the same-model system were around the same level in any laboratory. Presumably due to the noise from CPC and differences in the dilution method.

0.000

0.010

0.020

0.030

0.040

0.050

0.060

Full beforetest

Full after test Partial beforetest

Partial aftertest

PM

we

igh

t (m

g)

Lab. A

Lab. B

Error bar: ±σ

0.0001

0.001

0.01

0.1

1

10

Full beforetest

Full after test Partial beforetest

Partial aftertest

PN

C c

on

c. a

t VP

R o

utle

t (#

/cm3 )

Lab. A

Lab. B-Matter

Lab. B-SPCS1

Error bar: ±σ

0.0000

0.0010

0.0020

0.0030

0.0040

0.0050

0.0060

0.0070

0.0080

WHTCCold

WHTCHot

WHSC JE05

PM

em

issi

on

(g

/kW

h)

Lab. A

Lab. B

0.0000

0.0010

0.0020

0.0030

0.0040

0.0050

0.0060

0.0070

0.0080

WHTCCold

WHTCHot

WHSC JE05

PM

em

issi

on

with

ou

t TB

co

rre

ctio

n (

g/k

Wh

)

Lab. A

Lab. B

0.0000

0.0010

0.0020

0.0030

0.0040

0.0050

0.0060

WHTCCold

WHTCHot

WHSC JE05

PM

em

issi

on

with

ou

t TB

co

rre

ctio

n (

g/k

Wh

)

Lab. A

Lab. B

0.0000

0.0010

0.0020

0.0030

0.0040

0.0050

0.0060

0.0070

0.0080

WHTCCold

WHTCHot

WHSC JE05

PM

em

issi

on

with

ou

t TB

co

rre

ctio

n (

g/k

Wh

)

Lab. A

Lab. B

Effect of Tunnel Blank - Converted to mode emission -

19

TB levels of PM were high with the partial tunnel of Lab. A, and its contribution to the emission was also high.

PM calculated from TB-PM weight PM emission

Full tunnel

Partial tunnel

Full tunnel

Partial tunnel

PM calculated from TB-PM weight PM emission

20

Effect of Tunnel Blank - Converted to mode emission -

Since the effect of TB is affected by Vmix and power output of engine, the level of effect differs among modes.

* With Matter, TB contribution was about 1/100 to 1/1000; low effect on emissions.

* With SPCS, TB contribution was about 1/10 to 1/100; effect on some modes.

* The difference in the level of effect between Matter and SPCS is possibly due to the difference in the dilution method and the CPC noise level.

PN

1.0E+07

1.0E+08

1.0E+09

1.0E+10

1.0E+11

1.0E+12

WHTCCold

WHTCHot

WHSC JE05

PM

em

issi

on

(#

/kW

h)

Lab. A-SPCS1

Lab. B-Matter

Lab. B-SPCS1

1.0E+07

1.0E+08

1.0E+09

1.0E+10

1.0E+11

1.0E+12

WHTCCold

WHTCHot

WHSC JE05

PN

em

issi

on

(#

/kW

h)

Lab. A-SPCS1

Lab. B-Matter

Lab. B-SPCS1

Emission calculated from TB conc. Emission

21

Impact of PN Tolerance on PN Emission

Since the set dilution ratio was higher in Matter than SPCS, the level of effect was also higher in Matter.

Since the equipment specifications differed for each lab, the level of effect also differed for each test condition.

When the number of particles within the limit, 0.5 particle/cm3, was kept being measured, the calculated levels were the same as or exceeded the measured PN emission levels in some modes (WHTC-Hot, WHSC).

Regarding check procedure of R83 on pre-measurement (0.5 particle/cm3 or less when equipped with HEPA filter), the level of effect of this being measured as TB was calculated using the measured Vmix and power output.

1.0E+08

1.0E+09

1.0E+10

1.0E+11

1.0E+12

WHTCCold

WHTCHot

WHSC JE05

PM

em

issi

on

(#

/kW

h)

Lab. A

Lab. B-Matter

Lab. B-SPCS1

1.0E+08

1.0E+09

1.0E+10

1.0E+11

1.0E+12

WHTCCold

WHTCHot

WHSC JE05

PN

em

issi

on

(#

/kW

h)

Lab. A-SPCS1

Lab. B-Matter

Lab. B-SPCS1

Emission calculated from Tolerance Emission

22

Contents

Outline and Objective Round Robin Test Results Understanding the Factors Affecting the Measurement

Results Correlation of Two Counting Systems Sensitiveness of the Methods: PM & PN Effect of Filter Material on PM Emission

Summary

23

Correlation of SPCS-1 and Matter

Correlation of the two PNCSs was very good (coefficient of determination R2 > 0.99).

However, the linear approximation slopes had the value of about 0.8, which means the emissions measured by SPCS-1 were lower than those by Matter by about 20%.

y = 0.8026x R2 = 0.9975

1.0E+09

1.0E+10

1.0E+11

1.0E+12

1.0E+09 1.0E+10 1.0E+11 1.0E+12

PN emission with Matter PNCS (#/kWh)

PN

em

issi

on

with

Ho

rib

a P

NC

S (

#/k

Wh

)

WHTC-Cold WHTC-Hot WHSC JE05

y = 0.8042x R2 = 0.9988

1.0E+09

1.0E+10

1.0E+11

1.0E+12

1.0E+09 1.0E+10 1.0E+11 1.0E+12

PN emission with Matter PNCS (#/kWh)

PN

em

issi

on

with

Ho

rib

a P

NC

S (

#/k

Wh

)

WHTC-Cold WHTC-Hot WHSC JE05

Full tunnel Partial tunnel

24

Possible Factors for the Differences in the Results Differences in the correction method between two systems

Matter (JARI’s method) Particle type: NaCl particles produced by vaporization and condensation

method Concentration: About 800010000 particles/cm3

SPCS (Horiba’s method) Particle type: NaCl particles produced with atomizer Concentration: Varies depending on the particle size

Other factors Dilution method CPC measurement sensitivity …..

Fr calibration was performed on both systems according to the R83 regulations; however, there was a difference of 20% or more in their measurement results.Hence, the above factors need to be studied/discussed.

Since the possibility of the differences in the calibration method affecting the results cannot be denied, more detailed calibration procedures should be specified.

25

Sensitiveness of the Methods

* PM: Mode ratio (Hot/Cold) of the PM weight was constant, with or without soot loading.

* PN: Ratio (Hot/Cold) of the PN count was decreased by repetition, with or without soot loading.

* It is possible that DPF and other conditions cause experimental errors.

To improve the repeatability of PN measurement, more strict test procedures are necessary.

0

0.5

1

1.5

2

2.5

3

3.5

HOT_1 HOT_2 HOT_3

Full_PM

Partial_PM

0

0.1

0.2

0.3

0.4

0.5

0.6

HOT_1 HOT_2 HOT_30

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

HOT_1 HOT_2 HOT_3

Full_PN

Partial_PN

0

0.001

0.002

0.003

0.004

0.005

0.006

0.007

0.008

HOT_1 HOT_2 HOT_3

w/ soot loading w/o soot loadingPM

w/ soot loading w/o soot loadingPN

The results of the WHTC Hot tests repeated after WHTC Cold tests on that day (shown against the corresponding WHTC Cold test results)

-0.0005

0.0000

0.0005

0.0010

0.0015

0.0020

0.0025

0.0030

0.0035

0.0040

WHTC-Cold WHTC-Hot WHSC JE05

Test mode

PM

em

issi

on

(g

/kW

h)

Full tunnel （TX） - w/o TB correctitonFull tunnel （TX） - w TB correctionFull tunnel （Teflo) - w/o TB correctionFull tunnel （Teflo) - w TB correction

0.0000

0.0005

0.0010

0.0015

0.0020

0.0025

0.0030

0.0035

0.0040

WHTC-Cold WHTC-Hot WHSC JE05

Test mode

σ o

f PM

em

issi

on

(g

/kW

h)

Full tunnel(TX) - w/o TB correctionFull tunnel(TX) - w TB correctionFull tunnel(Teflo) - w/o TB correctionFull tunnel(Teflo) - w TB correction

0

50

100

150

200

250

300

350

WHTC-Cold WHTC-Hot WHSC JE05

Test mode

CO

V (

%)

Full tunnel(TX) - w/o TB correctionFull tunnel(TX) - w TB correctionFull tunnel(Teflo) - w/o TB correctionFull tunnel(Teflo) - w TB correction

26

Effect of Filter Material on PM Emission

* Since the effect of gas adsorption is small on Teflo filters, even the non-TB-corrected PM emissions measured with Teflo were lower than the TB-corrected emissions measured with TX40.

* Change of filter from TX to Teflo lowered PM emission levels, causing COV to be higher.* However, the use of Teflo made variations (standard deviation in g/kWh) smaller, resulting in the emissions around

the same level as TB-corrected TX-filter emissions (WHTC-Cold & Hot) or smaller (WHSC & JE05).

Emission

COV

Standarddeviation

27

Conclusion 1: Results of Repeated Tests PM:

Before TB correction, emission levels of the partial tunnel tended to be higher than the full tunnel, but TB correction reduced the difference between partial and full tunnels as well as the difference between labs.

TB correction lowered the emission levels, causing the apparent COV to be higher. However, it made the standard deviation (variations) smaller.

PN: Comparison between labs: The PN emission levels in WHTC-Cold and Hot were the same between

labs, but there were about 2- to 7-fold differences in WHSC and JE05. Comparison between full and partial tunnels: In Lab. A, the emission levels were the same between

full and partial tunnels, but in Lab. B, the partial tunnel emissions were double the full tunnel emissions in JE05. It is important to investigate the factors affecting the results, such as the differences in the dilution ratio, test environment, etc. among labs.

COV: The PM COV and PN COV were mostly around the same level. However, for PN, since the measurement results are largely affected by engine factors such as

deposition conditions of DPF, more detailed test procedures are necessary. Correlation of PM and PN emissions:

In the emissions from engines equipped with DPF, correlation of PM and PN emissions was small. TB correction:

PM: The correction reduced the difference among labs. PN: Depending on the equipment specs. (CVS flow rate) or test mode (power output), calculation

errors that exceed the levels of measured emissions from engines are possible to generate. Based on the current technologies, it is necessary to give sufficient consideration to the lower limit

that is measurable.

28

Conclusion 2: Factors Affecting the Results of PN Measurement While the correlation of the two PNCSs used in this test was

good, a difference of about 20% in the sensitivity was observed between SPCS and Matter.

The difference in the sensitivity of PNC can be corrected using the sufficient correction scheme that is currently available. However, the VPR PCRF correction method varies among manufacturers.

To minimize differences in the measurement results, it is necessary to prescribe more detailed provisions on those items that would affect the measurement results, such as the correction method.

PN emissions in the repeated tests decreased continuously. Therefore, it is necessary to establish detailed test procedures for PN measurement by giving sufficient consideration to the loading conditions of DPF.

29

Tasks for Particle Number Measurement To measure PN with good reproducibility, it is necessary to establish

strict test procedures including the preconditioning conditions, etc. TB correction on PM is an effective method for mitigating

differences among labs and/or systems. Depending on the equipment differences or test mode, it is possible

that tunnel blank/system blank-level particle concentrations will contribute to the PN emissions.

Sufficient consideration should be given to the lower limit for measurement.

In drafting the provisions on the PN calibration method, it is desirable to make modifications to the details: PCRF correction and its allowable range Strict regulations on particle species and concentration,

etc. for calibration particles

30

Appendix

Test System Diagram Correlation of PN and PN emission Effect of Dilution Ratio in PNCS Effect of Introducing-Hose Temperature Effect of Introducing-Pipe Length Effect of Micro Tunnel Sampling Position

31

Test System Overview (NTSEL)

AirAir

Filter Holder

Full Dilution Tunnel

Sample probe

HEPA and Charcoal Filter SPCS

Engine

Intake Air

AirAir

SecondaryTunnel

Primary Tunnel

Partial Flow Tunnel

Engine Exhaust

DPF

SPCS

for Full Flow

for Partial Flow

Filter Holder

Cyclone

32

CFVDilution Air

C

HEPA

Full dilution tunnel

Test engine

Engine dynamometer

PNCS1

MatterSystem

ASET15

Particle Massmeasurement 2nd tunnel

PNCS2

HoribaSystem

SPCS

Test System Overview (JARI Full Tunnel)

33

Test System Overview (JARI Micro Tunnel)

Test engine

Engine dynamometer

PNCS1

MatterSystem

ASET15

PNCS2

HoribaSystem

SPCS

Dilution Air

Particle Massmeasurement

(TX)

Vent

Partial Tunnel

34

Correlation of PM and PN emission

Correlation of PM and PN was low at the emission levels of DPF-equipped engines.

Relationship between PM and PN emissions was likely to differ among modes.

y = 8E+12x + 6E+10

R2 = 0.0087

0.0E+00

5.0E+10

1.0E+11

1.5E+11

2.0E+11

2.5E+11

3.0E+11

0.0000 0.0010 0.0020 0.0030 0.0040PM emission (g/kWh)

PN

em

issi

on

(#/

kWh

)

WHTC-Cold

WHTC-Hot

WHSC

JE05

y = 4E+13x + 3E+10

R2 = 0.1059

0.0E+00

5.0E+10

1.0E+11

1.5E+11

2.0E+11

2.5E+11

3.0E+11

0.0000 0.0005 0.0010 0.0015 0.0020 0.0025PM emission (g/kWh)

PN

em

issi

on (

#/kW

h)

WHTC-Cold

WHTC-Hot

WHSC

JE05

y = 2E+14x + 4E+10

R2 = 0.2321

0.0E+00

1.0E+11

2.0E+11

3.0E+11

4.0E+11

5.0E+11

6.0E+11

0.0000 0.0005 0.0010 0.0015 0.0020 0.0025PM emission (g/kWh)

PN

em

issi

on (

#/k

Wh

)

WHTC-Cold

WHTC-Hot

WHSC

JE05

y = 1E+14x + 4E+10

R2 = 0.225

0.0E+00

5.0E+10

1.0E+11

1.5E+11

2.0E+11

2.5E+11

3.0E+11

3.5E+11

4.0E+11

4.5E+11

0.0000 0.0005 0.0010 0.0015 0.0020 0.0025PM emission (g/kWh)

PN

em

issi

on (

#/k

Wh

)

WHTC-Cold

WHTC-Hot

WHSC

JE05

y = 3E+14x - 1E+10

R2 = 0.2709

0.0E+00

2.0E+11

4.0E+11

6.0E+11

8.0E+11

1.0E+12

1.2E+12

0.0000 0.0010 0.0020 0.0030 0.0040PM emission (g/kWh)

PN

em

issi

on (

#/kW

h)

WHTC-Cold

WHTC-Hot

WHSC

JE05

y = 2E+14x - 5E+09

R2 = 0.2548

0.0E+00

1.0E+11

2.0E+11

3.0E+11

4.0E+11

5.0E+11

6.0E+11

7.0E+11

8.0E+11

9.0E+11

1.0E+12

0.0000 0.0010 0.0020 0.0030 0.0040PM emission (g/kWh)

PN

em

issi

on (

#/kW

h)

WHTC-Cold

WHTC-Hot

WHSC

JE05

Full tunnel –Lab. A SPCS1 Full tunnel –Lab. B Matter Full tunnel –Lab. B SPCS1

Partial tunnel –Lab. A SPCS2 Partial tunnel –Lab. B Matter Partial tunnel –Lab. B SPCS1

y = 0.0177x + 104.81

R2 = 0.29980

20

40

60

80

100

120

10 100 1000

PND1 DF (Matter)

Ra

tio (

%)

y = 0.0126x + 105.42

R2 = 0.0188

0

20

40

60

80

100

120

0 20 40 60 80

PND1 DF (Horiba)

Ra

tio (

%)

y = 0.4178x + 98.226

R2 = 0.5860

20

40

60

80

100

120

0 2 4 6 8 10 12

PND2 DF (Matter)

Ra

tio (

%)

y = -0.1868x + 99.656

R2 = 0.7855

0

20

40

60

80

100

120

0 10 20 30 40 50

PND2 DF (Horiba)

Ra

tio (

%)

35

Effect of Dilution Ratio (PND1, PND2)PND1

In PND1, it was indicated that changes in the dilution ratio might affect the measurement results slightly.

In PND2, the effect on the measurement results was small in the dilution ratio range under PMP Recommend.

PND2 PMP Recommend

PMP RecommendPMP Recommend

PMP Recommend

36

Effect of Introducing-Hose Temperature

Comments:

* In WHTC-Cold mode, the PN (full flow/partial flow) decreased when the sample-introducing-hose temperature was 50C or below.

* No effect of temperature was observed in the repeated tests in WHTC-Hot mode.

Conclusion: If the hot hose is used, there will be no effect on the particle loss.

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

ambient 30℃ 50℃ 191℃

Fu

ll fl

ow

/ P

art

ial

flo

w

cold

hot1

hot2

Effect of introducing-hose heating on the particle loss

37

Effect of Introducing-Pipe Length

Comments:

* In WHTC-Cold mode, the PN decreased by 10% compared to the Hot mode.

* In WHTC-Hot mode, no effect of exhaust pipe length was observed.

* When sample was taken from the 2nd tunnel, the PN (full flow/partial flow) increased (cause unknown).

Conclusion: No effect of exhaust pipe length was confirmed.

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

2m 4m 2nd

Fu

ll fl

ow

/ P

art

ial

flo

w

cold

hot1

hot2

Differences in the particle loss depending on the introducing-pipe length and sampling position

0.0000

0.0002

0.0004

0.0006

0.0008

0.0010

0.0012

0.0014

0.0016

0.0018

0.0020

4m 10m

Length of sampling point

PM

em

issi

on

(g

/kW

h)

0.00E+00

5.00E+11

1.00E+12

1.50E+12

2.00E+12

2.50E+12

4m 10m

Length of sampling pointP

N e

mis

sio

n (

#/k

Wh

)

Matter

SPCS1

38

Effect of PT Sampling Position

PM (Mass) emission PN (Number) emission

* The average of the measurement results indicated that sampling position changes tended to decrease particle emissions for both PM and PN.

* However, there were relatively large variations in the results; hence, statistically speaking, it can be judged that there is little effect of the exhaust pipe length on the PM and PN emission levels.

Mode: WHTC-Hot Mode: WHTC-Hot

Full/Partial Ratio and PM & PN Emissions

* Full/Partial COV was improved for PN; therefore, the variations observed in the PN measurements are presumed to have been caused by variations in the engine exhaust.

0.0

0.5

1.0

1.5

2.0

2.5

3.0

WHTC

Cold

WHTC

Hot

WHSC

JE05

ETC ESC

Fu

ll flo

w /

Pa

rtia

l flo

w (

-)

Means of F/P PM

0.0

0.5

1.0

1.5

2.0

2.5

3.0

WHTC

Cold

WHTC

Hot

WHSC

JE05

ETC ESC

Fu

ll flo

w /

Pa

rtia

l flo

w (

-)

Means of F/P PN

0

50

100

150

200

WHTC

Cold

WHTC

Hot

WHSC

JE05

ETC ESC

CO

V (

%)

COVs of F/P PM

0

50

100

150

200

WHTC

Cold

WHTC

Hot

WHSC

JE05

ETC ESC

CO

V (

%)

COVs of F/P PN

39