R&D Powertrain | 2017-06-22

CPC CALIBRATION MATERIAL INTER-LABORATORY COMPARISON.

CPC CALIBRATION MATERIAL INTER-LABORATORY COMPARISON.

MOTIVATION.

CPC calibration material inter-laboratory comparison | R&D Powertrain | 2017-06-22 Page 2

Aerosol generators:

APG miniCAST (circulated)

miniCAST

Palas DNP

Silver

Emery Oil

Device under test:

PMP compliant CPC D50 = 23nm.

For engine exhaust measurements.

Material influence on CPC calibration.

Variation of calibration among 7 laboratories.

Variation among 7 in-house reference devices

and setups.

Harmonized calibration material in automotive

applications for:

CPC (Condensation Particle Counter).

VPR (volatile particle remover).

PN-PEMS.

PARTICIPANTS.

CPC calibration material inter-laboratory comparison | R&D Powertrain | 2017-06-22 Page 3

Time Laboratory Type

2/16 TSI Germany Instrument Manufacturer

3/16 JRC Research Institute

4/16 AVL Austria Instrument Manufacturer

6/16 PTB National Metrological Institute

7/16 BMW Vehicle Manufacturer

9/16 Ricardo E&E Calibration Service

11/16 VW Vehicle Manufacturer

12/16 TSI Germany Instrument Manufacturer

PROCEDURE.

1 aerosol generator propane flame.

APG (miniCAST + thermal treatment)

1 reference CPC D50 = 10nm.

TSI 3792E

2 engine exhaust CPC D50 = 23nm.

TSI 3791

AVL CPC (pre-production)

CPC calibration material inter-laboratory comparison | R&D Powertrain | 2017-06-22 Page 4

Circulated instruments. Data Handling.

Evaluation at BMW.

Standardized data correction at BMW.

- Electrometer zero, double charges

- Reference K-factor

- Flow

Data collection by JRC.

Calibration at participating laboratories.

Circulated generator In-house generators

!

!

circulated

circulated

CALIBRATION SETUP.

Note: not all labs use an ISO 27891 compliant setup (2-way splitter).

CPC calibration material inter-laboratory comparison | R&D Powertrain | 2017-06-22 Page 5

Dilution

Particle source 1

(circulated)

Particle source 2

(in-house)

… DMA

Thermal

treatment

HEPA Make-up air

Device under Test

Engine Exhaust CPC

PMP compliant

23nm D50

Reference

AEM/CPC

In-house

ENGINE EXHAUST CPC CALIBRATION: RAW DATA.

CPC calibration material inter-laboratory comparison | R&D Powertrain | 2017-06-22 Page 6

Calibration Curve: APG generator, Reference 23nm CPC, all laboratories.

- Error bar: multiple measurements

from one lab.

- Standardized correction applied.

Calibration certificate value

ENGINE EXHAUST CPC CALIBRATION: RAW DATA.

CPC calibration material inter-laboratory comparison | R&D Powertrain | 2017-06-22 Page 7

Calibration Curve: APG generator, Reference 23nm CPC, all laboratories.

- Error bar: multiple measurements

from one lab.

- Standardized correction applied.

Calibration certificate value

ENGINE EXHAUST CPC CALIBRATION: MATERIAL.

CPC calibration material inter-laboratory comparison | R&D Powertrain | 2017-06-22 Page 8

All data at 23nm.

- All Data submitted for 23nm.

- Standardized correction applied.

- Error bar: Indicates multiple measurements

submitted by one laboratory.

Calibration certificate value

PMP D50 +/- 12%

ENGINE EXHAUST CPC CALIBRATION: MATERIAL.

CPC calibration material inter-laboratory comparison | R&D Powertrain | 2017-06-22 Page 9

- All Data submitted for 41nm.

- Standardized correction applied.

- Error bar: Indicates multiple measurements

submitted by one laboratory.

Calibration certificate value

PMP D90

All data at 41nm.

ENGINE EXHAUST CPC CALIBRATION: MATERIAL.

- Smaller difference between soot-like and emery oil.

- Smaller standard deviation as for 23nm.

- Soot-like aerosols APG, CAST, Palas very similar.

- Emery Oil shows significant difference.

CPC calibration material inter-laboratory comparison | R&D Powertrain | 2017-06-22 Page 10

Average data at 23nm.

Average data at 41nm.

PMP D50 +/- 12%

PMP D90

6 la

bs

5 la

bs

4 la

bs

2 la

bs

3 la

bs

6 la

bs

5 la

bs

4 la

bs

1 la

b

3 la

bs

ENGINE EXHAUST CPC CALIBRATION: MATERIAL.

CPC calibration material inter-laboratory comparison | R&D Powertrain | 2017-06-22 Page 11

Calibration Curve: Material Comparison.

- In-house CAST: Small error bars even for

5 different devices and setups.

Advantage of a well-known setup.

ENGINE EXHAUST CPC CALIBRATION: MATERIAL.

CPC calibration material inter-laboratory comparison | R&D Powertrain | 2017-06-22 Page 12

Calibration Curve: Material Comparison.

- In-house CAST: Small error bars even for

5 different devices and setups.

Advantage of a well-known setup.

- Silver efficiency curve shows good

correlation with soot.

ENGINE EXHAUST CPC CALIBRATION: MATERIAL.

CPC calibration material inter-laboratory comparison | R&D Powertrain | 2017-06-22 Page 13

Calibration Curve: Material Comparison.

- In-house CAST: Small error bars even for

5 different devices and setups.

Advantage of a well-known setup.

- Silver efficiency curve shows good

correlation with soot.

- Emery Oil has much steeper cut-off.

- Small error bars for silver/emery oil: (!)

low number of labs.

LESSONS LEARNED: CPC COMPARISON.

Similar performance of TSI and AVL engine exhaust CPC.

Only Electrometer and sub-10nm CPC as reference for 3792E.

Instabilities: larger error bars for 3792E.

CPC calibration material inter-laboratory comparison | R&D Powertrain | 2017-06-22 Page 14

Circulated APG miniCAST. In-house miniCAST.

LESSONS LEARNED: GENERATOR SIZE DRIFT.

Mode range: 21nm – 30.4nm.

CPC calibration material inter-laboratory comparison | R&D Powertrain | 2017-06-22 Page 15

APG generator operating point “B” for 23nm. APG generator operating point “C” for 41nm.

Mode range: 13nm – 18.1nm.

Contamination: generator cleaned at VW (after Ricardo).

0.0

0.2

0.4

0.6

0.8

1.0

10 100

Nor

mai

lzed

PN

Mobility Diameter [nm]

JRC

AVL

BMW

Ricardo

VW

0.0

0.2

0.4

0.6

0.8

1.0

10 100

Nor

mai

lzed

PN

Mobility Diameter [nm]

JRC

AVL

BMW

Ricardo

VW

CONCLUSION.

Comprehensive comparison of aerosol sources and setups.

Soot identified as candidate aerosol for harmonization of calibration in automotive exhaust applications.

Good correlation of in-house soot generators in spite of different burners and aerosol after-treatment.

Significant differences between emery oil and soot-like at small particle sizes (important for automotive testing).

CPC calibration material inter-laboratory comparison | R&D Powertrain | 2017-06-22 Page 16

CONCLUSION.

Comprehensive comparison of aerosol sources and setups.

Soot identified as candidate aerosol for harmonization of calibration in automotive exhaust applications.

Good correlation of in-house soot generators in spite of different burners and aerosol after-treatment.

Significant differences between emery oil and soot-like at small particle sizes (important for automotive testing).

Open questions:

What is the quantitative uncertainty of soot calibration?

What is the influence of the laboratory setup?

CPC calibration material inter-laboratory comparison | R&D Powertrain | 2017-06-22 Page 17

PMP Sub-Group

“PNC Calibration“ led by PTB

2nd stage of the Comparison Exercise

ACKNOWLEDGEMENTS.

Thank you to all the participants of the Round Robin

for their effort, advice and support.

JRC: Barouch Giechaskiel

PTB: Volker Ebert, Andreas Nowak, Johannes Rosahl

Ricardo: Jason Southgate, Ian Marshall

AVL: Athanasios Mamakos, Martin Cresnoverh

VW: Sebastian Usarek, Manuel Kaatz

TSI: Hans-Georg Horn

BMW: Heinz Bacher

And many other contributors!

CPC calibration material inter-laboratory comparison | R&D Powertrain | 2017-06-22 Page 18