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