MAGEE Scientific Aethalometer AE33 User manual

Aethalometer
Model AE33
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User's manual –Ver. 1.53 July 2015 1/75
Aethalometer®Model AE33
User Manual
Version 1.53
July 2015
Aerosol d.o.o., Ljubljana, Slovenia

Aethalometer
Model AE33
____________________________________________________________________________________________________________
User's manual –Ver. 1.53 July 2015 2/75
Aethalometer® Model AE33 Manual
Version 1.53, July 2015
Applicable for AE33-Software ver. 1.1.7.1
Copyright 2012 Aerosol d.o.o. Magee Scientific Aethalometer® Manual. All Rights Reserved.
Licensed OEM distributors only are allowed to use the contents of this manual with their own
names, trademarks and logos for branding purposes for the distribution of Aethalometer®
instruments, but may not modify the text without the prior written permission of Aerosol
d.o.o. and must include the copyright notice in italics above on all copies.
Aerosol d.o.o.
Kamniška 41
SI-1000 Ljubljana
Slovenia, EU
tel: [phone]
fax: [phone]
www.aerosol.eu
www.magescientific.com

Aethalometer
Model AE33
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User's manual –Ver. 1.53 July 2015 3/75
TABLE OF CONTENTS
1.1 Description of the instrument..................................................................................................... 5
1.2 Technical specification............................................................................................................. 14
1.3 Basic calculations..................................................................................................................... 15
1.4 Functional description of the instrument.................................................................................. 16
1.5 Flow manifold.......................................................................................................................... 22
2 SAFETY NOTES and LABELS ..................................................................................................23
3 IDENTIFICATION and MARKINGS.........................................................................................27
3.1 Instrument identification label ................................................................................................. 27
3.2 Front panel markings................................................................................................................ 27
3.3 Back panel markings................................................................................................................ 27
4. INSTRUMENT INSTALLATION ..............................................................................................28
4.1 Unpacking the system .............................................................................................................. 28
4.2 The sampling line..................................................................................................................... 28
4.3 Switching the Aethalometer on................................................................................................ 30
4.4 Filter tape installation............................................................................................................... 33
4.5 Installation of instrument in the measurement station ............................................................. 40
5 USER INTERFACE, SETTINGS and OPERATION ..................................................................41
5.1 User interface and settings ....................................................................................................... 41
5.2 Instrument Status...................................................................................................................... 44
5.3 Downloading and Viewing Data.............................................................................................. 47
5.4 Connecting to External Datalogger or PC................................................................................ 52
5.5 Serial Commands for Communication with the Aethalometer................................................ 53
5.6 External devices ....................................................................................................................... 54
5.6.1 AMES_TPR159 .................................................................................................................... 55
5.6.2 Comet_T0310........................................................................................................................ 55
5.6.3 Vaisala_GMP343 .................................................................................................................. 55
5.6.4 TSI_4100............................................................................................................................... 55
5.6.5 Datalogger_AE33_protocol .................................................................................................. 56

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Model AE33
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5.6.6 Aerosol_inlet_dryer............................................................................................................... 56
5.6.7 Dataloger Bayern Hessen protocol........................................................................................ 56
5.6.8 Datalogger Qair protocol....................................................................................................... 57
5.7 Software upgrade...................................................................................................................... 59
5.8 BC source apportionment......................................................................................................... 60
5.9 Screen saver.............................................................................................................................. 62
6 MAINTENANCE and SERVICE.................................................................................................63
6.1 Automatic flow-meter calibration............................................................................................ 64
6.2 Manual flow-meter calibration................................................................................................. 65
6.3 Leakage test.............................................................................................................................. 66
6.4 Manual stability test ................................................................................................................. 67
6.5 Manual clean air test ................................................................................................................ 68
6.6 Automatic clean air test............................................................................................................ 69
6.7 Tape sensor calibration............................................................................................................. 69
6.7 Flow verification...................................................................................................................... 70
6.8 ND filter test............................................................................................................................. 71
6.9 Inlet leakage test....................................................................................................................... 71
7. TROUBLESHOOTING GUIDE ............................................................................................72
7.1 Startup screen checks............................................................................................................... 72
7.2 Instrument status ...................................................................................................................... 73
7.3 Unacceptable quality control test results.................................................................................. 74
7.4 Other problems......................................................................................................................... 74
8 TECHNICAL SUPPORT and CONTACT INFORMATION ......................................................75

Aethalometer
Model AE33
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1 INTRODUCTION
1.1 Description of the instrument
Figure 1. The Aethalometer® Model AE33.
Magee Scientific and Aerosol Co. are pleased to announce the ‘Next Generation’
Aethalometer®, Model AE33. This development incorporates scientific and technical
advances designed to offer improved measurement performance, user features,
communications and interface, and the ability to perform routine performance tests to verify
correct operation. Most importantly, the instrument incorporates the patented DualSpot™
measurement method. This provides two significant advantages: elimination of the changes
in response due to ‘aerosol loading’ effects; and a real-time calculation of the ‘loading
compensation’ parameter which offers insights into aerosol optical properties, and has been
interpreted in models of aerosol origins and aging.

Aethalometer
Model AE33
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The Aethalometer Model AE33 has been developed with input from the research and
monitoring communities, and is designed for reliable operation under all conditions ranging
from state-of-the-art research to compliance monitoring.
The leading innovations incorporated into the Model AE33 include:
1. The DualSpot™ measurement method, which solves the effects common to all filter-
based real-time monitors, in which the instrumental response factor shows a dependence on
the loading of material on the filter.
2. Features for automatic ‘dynamic zero’ testing under a flow of internally-generated
clean air; ‘span’ testing of the response of the optical sources and detectors; calibration of the
response of the internal mass flow meters, if an external standard flow calibrator is connected;
and validation of the photometric response by use of a kit of ‘Neutral Density’ optical filters
whose properties may be traced to reference standards.
3. User and communications interfaces, permitting remote monitoring of operation; data
retrieval; performance of internal tests; and reporting of ‘state-of-health’ parameters.
4. Modular construction designed for ease of routine maintenance service.
In addition to the above features, the Aethalometer Model AE33 offers real-time aerosol
absorption analysis at up to ten optical wavelengths, with rapid time resolution to 1 second
even in 10-wavelength mode. This permits the measurement of optically-absorbing aerosols –
‘Black’ Carbon and ‘Brown’ Carbon components of particulate matter – in applications
including routine monitoring of ambient air quality for regulatory purposes; measurements of
the concentration of BC in urban, suburban, regional, rural and remote locations; source
testing; and laboratory-based research.

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Model AE33
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‘DualSpot™’ technology
The Aethalometer Model AE33 uses the patented DualSpot™ method to compensate for the
‘spot loading effect’; and also to provide a real-time output of the ‘loading compensation’
parameter, which may provide additional information about the physical and chemical
properties of the aerosol.
The ‘spot loading effect’ is a variable phenomenon which appears as a gradual reduction of
instrumental response as the aerosol deposit density of the filter tape increases from zero to
the predetermined limit of ‘Maximum Attenuation’ (Gundel 1984, Weingartner 2003, Arnott
2005, Virkkula 2007, Kanaya 2008, Hyvärinen 2012). When the filter tape advances to a fresh
spot, the data undergoes a discontinuous jump from its previous lower value, calculated when
the spot was heavily loaded; to a higher value, calculated from collection on a fresh spot at
zero loading. In the Aethalometer the reduction of data at increasing loadings is well
described by a linear function of attenuation, but its magnitude cannot be predicted: some
aerosols in some locations in some seasons may show a small or zero ‘loading effect’; while
under other conditions, the effect may be larger and noticeable. Empirically, it is found that
fresher aerosols closer to their combustion sources will show a larger ‘spot loading effect’;
while well-aged aerosols under atmospheric conditions of high chemical activity and oxidative
processing may show an almost zero effect. The effect is revealed statistically by processing
data collected over a large number of tape advances, representing many data points collected
at loadings (‘ATN values’) ranging from zero to the preset maximum. The data is collected into
bins according to loading (attenuation, ATN). If there is a systematic reduction of the
calculated result as a function of loading, the data will show a clear negative slope, with the
intercept representing the ‘zero loading’ value. Figure 2 illustrates two datasets from urban
locations with loading effects either present or not.

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Model AE33
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Figure 2. Aethalometer data sorted and averaged according to loading (attenuation, ATN) on spot –
roadside location in London, UK (top); urban site in Boston (Roxbury), USA (bottom).

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Model AE33
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The London data show a systematic reduction at increasing loadings; while the Boston data do
not. This demonstrates that any method intended to compensate for the ‘spot loading effect’
must be auto-adaptive and able to adjust dynamically to different situations. An instrument
based on firmware with a fixed ‘loading non-linearity’ parameter will not operate correctly at
all locations. The ‘loading non-linearity’ parameter must be measured.
It is clear that the effect, when present, is linear with loading (‘ATN’). This can be represented
as
BC (reported) = BC (zero loading) * { 1 - k • ATN }
where BC (zero loading) is the desired ambient BC value that would be obtained in the
absence of any loading effect; and k is the ‘loading compensation parameter’ (similar to
Virkkula, 2007).
The analysis of a large number of datasets from a wide variety of locations shows that this
relationship is linear in all cases studied; but with different values of k. It is therefore possible
to eliminate the ‘loading effect’ of k by making two simultaneous identical measurements BC1
and BC2 at different degrees of loading ATN1 and ATN2.
BC1 = BC * { 1 - k • ATN1 }
BC2 = BC * { 1 - k • ATN2 }
From these two linear equations we may calculate the ‘loading compensation parameter’ k;
and the desired value of BC compensated back to zero loading.
The Aethalometer Model AE33 Aethalometer Model AE33 analyzes the Black Carbon
component of aerosols on two parallel spots drawn from the same input stream, but collected

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Model AE33
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at different rates of accumulation, i.e. at different values of ATN. By combining the data
according to the above equations, the AE33 yields the value of BC extrapolated back to ‘zero
loading’; as well as a real-time output of the ‘loading compensation parameter’ k which
provides insights into the aerosol nature and composition. This process is performed in real
time for all wavelengths: examination of the ‘k’ values as a function of wavelength provides
further information about the aerosol composition. An example of this is shown for extreme
concentrations of black carbon (Figure 3).
Figure 3. The time-series of AE33 raw and compensated BC concentrations with 1 second timebase –note
the extreme concentrations and loading effects.
Automatic Zero and Span
The Aethalometer Model AE33 offers the capability for automatically checking the ‘zero-air’
response of the instrument under dynamical operating conditions. This test is implemented
by back-flushing the inlet connection with an excess flow of internally-filtered air and
circulating the filtered air in the instrument. The data reported during this period are analyzed
for the mean value and the point-to-point variation. The mean value should be close to zero
under ideal conditions; any positive value greater than zero represents the leakage of BC-
containing room air into the instrument’s analytical zone. The point-to-point variation
represents the instrument’s measurement noise level under actual operating conditions of
2000 3000 4000
0
20000
40000
60000
80000
BC concentration (ng/m3)
time (sec)
IR, 1 second
raw BC1
raw BC2
compensated BC