Droplet SP2-XR User manual

Operator Manual
2400 Trade Centre Avenue
Longmont, CO 80503 USA
DOC-0425 Revision D
A L L R I G H T S R E S E R V E D
SP2-XR
Single Particle Soot Photometer -
Extended Range

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C O N T E N T S
Specifications ................................................................................................................. 6
1.1 General Specifications for the SP2 XR................................................................................... 6
1.2 Electrical Specifications......................................................................................................... 7
1.3 Recommended Maintenance................................................................................................ 7
1.4 Physical Specifications........................................................................................................... 7
General Information....................................................................................................... 8
1.5 Safety Information ................................................................................................................ 9
1.6 Interface Features ............................................................................................................... 10
1.7 Brief Theory of Operation ................................................................................................... 11
Introduction ..................................................................................................................14
Unpacking, Setup, Installation, and Power Up................................................................18
1.8 Unpacking............................................................................................................................ 18
1.9 Installation........................................................................................................................... 18
1.10 Setup ................................................................................................................................... 18
1.11 Powering the System Down ................................................................................................ 20
SP2-XR Software............................................................................................................21
1.12 Output Data file types ......................................................................................................... 21
1.13 SP2-XR Quick-Start .............................................................................................................. 22
1.14 SP2-XR Main Screen ............................................................................................................ 26
1.15 Histograms Tab.................................................................................................................... 27
1.16 Config Tab............................................................................................................................ 28
Config / Acquisition Tab............................................................................................................... 30
Config / Settings Tab.................................................................................................................... 31
Config / Alarms Tab ..................................................................................................................... 31
Config / Sequences Tab................................................................................................................ 33
Config / Custom Tab .................................................................................................................... 34
1.17 Alarms Tab........................................................................................................................... 35
Examples of how to set parameters for Alarms .......................................................................... 35
1.18 System Settings tab ............................................................................................................. 38
1.19 Utility Window..................................................................................................................... 39
Utility –Data Reader ................................................................................................................... 39
Utility –Log reader ...................................................................................................................... 40
1.20 Status Window .................................................................................................................... 41
Laser Beam Profiler Software.........................................................................................42
1.21 Camera Preparation ............................................................................................................ 42
1.22 Running the software.......................................................................................................... 46

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Laser Safety Interlocks .................................................................................................. 49
Routine Maintenance ................................................................................................... 50
1.23 Cleaning the Laser Optics ....................................................................................................50
Troubleshooting ........................................................................................................... 52
Additional Questions .................................................................................................... 52
Appendix A: Expanded Theory of Operation.................................................................. 53
Appendix B: Warranty and Contact Information............................................................ 56
Appendix C: Particle Size / Shape determination ........................................................... 57
Appendix D: Particle by Particle data files ..................................................................... 58
Appendix E: Housekeeping data files............................................................................. 60
Appendix F: Single Particle Trace Files ........................................................................... 62
Appendix G: Mounting Information .............................................................................. 63

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F i g u r e s
Figure 1: SP2-XR Labels................................................................................................... 9
Figure 2: Front and Rear view of the SP2-XR...................................................................10
Figure 3: SP2-XR Aerosol Flow........................................................................................13
Figure 4: SP2-XR Power Connections and Cables ............................................................19
Figure 5: SP2-XR Power Switch ......................................................................................19
Figure 6: SP2-XR Screen with Actions Tab.......................................................................20
Figure 7: SP2-XR Default Screen .....................................................................................22
Figure 8: Check the Config file and Status.......................................................................23
Figure 9: Choosing parameters.......................................................................................24
Figure 10: File tab ..........................................................................................................25
Figure 11: Data File tab..................................................................................................25
Figure 12: SP2-XR Main Screen ......................................................................................26
Figure 13: Histograms window: Scatter (blue) and Incandescent (red) ............................27
Figure 14: Config / Programs tab....................................................................................28
Figure 15: Config / Acquisition tab .................................................................................30
Figure 16: Config / Settings tab ......................................................................................31
Figure 17: Config / Alarms tab........................................................................................32
Figure 18: Config / Sequences tab ..................................................................................33
Figure 19: Config / Custom tab.......................................................................................34
Figure 20: Alarms tab.....................................................................................................35
Figure 21: System Settings tab .......................................................................................38
Figure 22: Utility –Data Reader .....................................................................................39
Figure 23: Utility Log Reader..........................................................................................40
Figure 24: Status tab......................................................................................................41
Figure 25: SP2-XR front panel screws .............................................................................42
Figure 26: Front panel connections ................................................................................43
Figure 27: Laser power monitor board ...........................................................................43
Figure 28: Laser power board removal ...........................................................................44
Figure 29: Laser power board removed ..........................................................................44
Figure 30: Front panel connections 2 .............................................................................45
Figure 31: vBeam application.........................................................................................46
Figure 32: Video board selection....................................................................................46
Figure 33: Resolution and bit depth selection.................................................................47
Figure 34: vBeam play button ........................................................................................47
Figure 35: vBeam exposure time....................................................................................48
Figure 36: Cabinet Interlock Switch ................................................................................49

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Figure 37: SP2-XR Key in the locked (laser off) position.................................................. 49
Figure 38: Cleaning port access to optics ....................................................................... 50
Figure 39: Cleaning the Optics ....................................................................................... 51
Figure 41: SP2-XR Aerosol Flow ..................................................................................... 54
Figure 42: SP2-XR Optical Diagram ................................................................................ 55
Figure 43: SP2-XR Particle trace schematic .................................................................... 57
Figure 44: SP2-XR Mounting Hole Dimensions ............................................................... 63

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Specifications
Specification are subject to change without notice.
1.1 General Specifications for the SP2 XR
Measured Parameters
•Laser (Nd:YAG Laser: 1064 nm) incandescence by single-particle
•Light scattering by single-particle
Derived Parameters
•Refractory Black Carbon mass
•Particle number
•Optical Particle Size
Particle Size Range
•Scattering signal: 100 –500 nm optical diameter
•Incandescent signal: 50nm –800 nm mass-equivalent diameter
assuming a black carbon density of 1.8 g/cm3
Maximum Data Acquisition Rate
•50,000 particles / cm3
•10% coincidence at 3,000 Particles/ cm3
Sample Flow Required
30 –120 volumetric cm3/minute user programmable
Sample Inlet Pressure Range
400 mbar –1013.25 mbar (1 atm)
Sample Temperature Range
0°C to 40°C (32° - 104°F)
Operating Temperature Range
0°C to 40°C (32° - 104°F)
Storage Temperature Range
-20°C to 50°C (-4° - 122°F) non-condensing
Operating Humidity
5 to 95% non-condensing
Data Storage Capacity
400GB –15 days of continuous data storage with nominal sample
concentration of 1,000 particles / cm3and a standard flow rate of
100 volumetric cm3/minute.

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1.2 Electrical Specifications
Power Requirements:
•90 –230 / 50-60 Hz with DMT supplied power supply
•18-36VDC, (24V Nominal) with direct power connection:
oPower connector is part number RT00104PNH and it mates
with RT06104SNH
oPower surge protection is highly recommended
Power Consumption:
25 W typical / 85 W maximum
Backup Battery Capacity
10.24Wh
Front Panel Connections
VGA and HDMI monitor ports, Two Ethernet ports, 2x USB 3.0 ports,
and 2x USB 2.0 ports. 1/8 in. Swagelok® sample connection line, 1/4
in. Swagelok® exhaust line, fan inlet.
1.3 Recommended Maintenance
Weekly Routine Maintenance:
Conduct PSL size check to verify calibration
Monthly Maintenance
(and around field campaigns):
Conducting zero check with high-efficiency filtered air sample.
Annual Maintenance and
Recommended Service
Annual cleaning and calibration at a DMT certified service facility
under normal operating conditions, may need service on a more
frequent basis depending on type of environment where the
instrument is being used.
1.4 Physical Specifications
Weight:
13 Kg (28.5lbs) for SP2-XR Instrument
Dimensions:
21 cm W x 21 cm H x 42 cm L (Actual) Not including inlet hardware
and fuses.
Shipping Container:
61 cm W x 35.5 cm H x 63.5 cm L (Actual)
32.3 Kg (69 lbs.)

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General Information
In no event will Droplet Measurement Technologies, LLC (DMT) be liable for direct, indirect, special,
incidental or consequential damages resulting from any defect or omissions in this manual.
DMT reserves the right to make changes to this manual and the products it describes at any time,
without notice or obligation. Revised editions are found on the manufacturer’s website.
All DMT product names and the Droplet Measurement Technologies Logo are trademarks of Droplet
Measurement Technologies, LLC.
All other brand and product names are trademarks, or registered trademarks, of their respective
owners.
Software License
This software is provided by DMT “as is” and any express or implied warranties, including, but not
limited to, the implied warranties of merchantability and fitness for a particular purpose are
disclaimed. Under no circumstances and under no legal theory, whether in tort, contract, or
otherwise, shall DMT or its developers be liable for any direct, indirect, incidental, special, exemplary,
or consequential damages (including damages for work stoppage; computer failure or malfunction;
loss of goodwill; loss of use, data or profits; or for any and all other damages and losses). Some states
do not allow the limitation or exclusion of implied warranties and the user may be entitled to
additional rights in those states.

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1.5 Safety Information
Laser Safety
The SP2-XR is a Class 1 Laser Product when fully enclosed. Removing the outer enclosure, or the power monitor
will expose a Class IIIB laser, 1064 nm, with power of approximately 200 mW. Disassembly of the pump laser
can expose a Class 4, 808 nm with power up to 3W. Lasers in this category can cause permanent eye damage
with exposures of 1/100th of a second or more depending on the strength of the laser. A diffuse reflection is
generally not hazardous but specular reflections can be just as dangerous as direct exposure. Protective
eyewear is recommended when direct beam viewing of this class of lasers may occur. Lasers at the high-power
end of this class may also present a fire hazard and can burn skin.
CAUTION –Use of controls, adjustments, or performance of procedures other than those specified herein
may result in hazardous radiation exposure. Strict observance of the following Warning labels is advised.
Back panel of the SP2-XR
Back panel of the SP2-XR
Interlock switches:
Exterior of the laser frame:
Figure 1: SP2-XR Labels

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1.6 Interface Features
The SP2-XR input and output features are shown in Figure 2 below
Figure 2: Front and Rear view of the SP2-XR
1
Power switch
6
HDMI Port
2
Function indicators
7
Monitor Port (VGA)
3
Inlet flow (remove plug prior to power-up)
8
Ethernet ports
4
Exhaust flow (remove plug prior to power-up)
9
24 VDC power connection
5
USB 3.0/2.0 ports
10
Optional Ground/Fuse drawer
1
2
4
3
5
6
7
8
9
10

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1.7 Brief Theory of Operation
The Single Particle Soot Photometer (SP2-XR) utilizes a high optical power intracavity Nd:YAG laser
to interrogate particles, which both scatter light and absorb energy. The system captures the peak
scattered light signals that are generated for each particle. These signals are used for particle sizing,
since the amount of light scattered correlates strongly with particle size.
Light-absorbing particles, mainly refractory black carbon (rBC), absorb energy and are heated to the
point of incandescence. The energy emitted in this incandescence is measured, and a quantitative
determination of the rBC mass of the particle is made. This mass measurement is independent of the
particle mixing state, and hence the SP2-XR is a reliable measure of the black carbon mass
concentration. Since the SP2-XR detects single particles, the SP2-XR also measures the black carbon
mass concentration.
All particles scatter light, regardless of whether or not they incandesce. A scattering detector is
included in the SP2-XR, which detects single particle scattering at 1064 nm. The scattering detector
can be used to detect non-BC-containing aerosol number and optical particle size.
The SP2-XR uses a sample flow controller to control the flow rate of aerosol sample pulled into SP2-
XR. The sample is drawn through the sample inlet and then injected into the optical cavity and
surrounded by the recirculating sheath flow air system to ensure that the particles are directed
through the laser beam. This enables the system to sample each individual particle in the sample
stream.
A single particle scattering measurement is made and a determination as to whether the scattering
measurement represents a particle is made. Subsequently, if the particle is Black Carbon, it will
absorb the energy from the high optical power intracavity Nd:YAG laser and then incandesce; this is
measured along with a determination as to whether the incandescence represents a particle. Figure
3 shown below details the flow system.
The instrument consists of 5 general subsystems, described in this section:
1) Main optical subsystem—generates the laser light, detects the light scattered by particles,
collects the incandescence, and provides a mechanical enclosure for the optical system and
for delivery of the sample aerosol
2) Flow system—brings the sample aerosol through the optical interaction region, controls
and measures the flows
3) Analog electronics system—amplifies and processes the particle signals
4) Digital electronics system—analyzes particle signals, bins signals according to user-specified
bin mappings, generates a histogram of particles in the specified bins, and communicates
with the PC and system monitor/control functions
5) Onboard PC—allows user to control instrument and collect and report data

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Figure 3: Block Diagram of the SP2-XR
Particle
photo-
signal
Digital electronics (4)
PC and Display (5)
Monitor and
control
Histogramming
functions
Analog signal
processing (3)
Optical
system (1)
(2) Flow
system
Flow control
and monitor
laser control
and
monitor
Flow
Analog monitor
Analog
particle
peak
detector

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Figure 3: SP2-XR Aerosol Flow
Once the sample passes through the optical cavity it will flow through several filters and then either
be used as make-up air for the sheath flow, or it will be ejected through the outlet of the SP2-XR
depending on the setting for the sheath flow.
Refer to Appendix A for an expanded discussion on the Theory of Operations.

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Introduction
Black carbon or soot particles are ubiquitous in the atmosphere and are emitted by combustion processes.
They play a major role in climate forcing by absorbing solar radiation and re-radiating the energy as heat.
In addition, black carbon aerosol from open air cooking, contributes to over 4 million deaths worldwide
(World Health Organization). Accurate measurements of black carbon particle concentration and temporal
and spatial variability are essential for estimating their radiative effects in the atmosphere as well as their
effects on human health.
The Single Particle Soot Photometer-Extended Range (SP2-XR) directly measures refractory black carbon
(rBC) in individual particles. It uses the same laser-induced incandescence technology as the DMT SP2-D,
but with a modified optical design that allows it to be better suited for long-term monitoring applications.
In addition to a smaller footprint, the software and firmware included with the SP2-XR provides final data
output in real time without the need for two pass processing.
The SP2-XR utilizes a high optical power intracavity Nd:YAG laser. Light absorbing particles, mainly rBC,
absorb energy and are heated to the point of incandescence. The energy emitted during incandescence is
measured and a quantitative determination of black carbon mass of the particle is made. This mass
measurement is independent of the particle mixing state, and hence the SP2-XR is a reliable measure of
the black carbon mass concentration. Since the SP2-XR detects single particles, this highly sensitive
instrument is ideal for monitoring in remote environments.
oOptical System
The optical system consists of several parts: the laser and associated components and optics; the
detection system, including collection optics, photodetectors, and reference monitoring; and the
mechanical housing.
The Laser
The laser is a semiconductor-diode-pumped Nd3+:YAG solid-state laser. It operates in the
fundamental (TEM00) spatial mode on a 1064 nm laser line with an intra-cavity power of ~1 kW. The
pump laser is a temperature-controlled 1 W single-stripe diode at 808 nm, driven by a stable
current source. The Nd3+:YAG laser is a high quality factor optical resonator built around an
Nd3+:YAG active laser crystal, pumped end-on by the diode laser. The laser mirrors have
reflectivities near 0.99999 at the lasing wavelength. The laser mode has a 1/e2intensity diameter of
600 µm. The standing wave laser mode is perpendicular to the flow of particles. Particle scatter is
collected in a direction perpendicular to both the particle flow and the laser standing-wave; see
Figure 4 and Error! Reference source not found. for side and top views of the optical block.

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The Detection System
The detection system consists of two pairs of Mangin collection optics capable of collecting light
over a large solid angle. The Mangins image the space at which the sample flow intersects the laser
mode. The first pair of collection optics, the primary scattering detection system, images onto an
avalanche photodiode (APD) for detecting the particle sizing signal. The other pair, the
incandescence detection system, images onto a PMT module. The two detection systems are
located on the opposite sides of the optic block.
Each detector is amplified in a current-to-voltage stage that feeds into the analog electronics
system. The amplification allows the system to detect particles as small as 50 nm and 1-10
counts/minute at a zero-count rate in the incandescence channel and 100nm and 1-10
counts/minute at a zero-count rate in the scattering channel. At this particle size, the peak scatter
rate corresponds to ~100 pW of detected light power at the detector. The size sensitivity is limited
by several factors, including a fundamental noise process from the photon-shot noise on the
detected molecular scatter from background gas, and a fundamental noise process from the
Johnson noise in the photodiode transimpedence feedback resistor.
The imaging optics have an acceptance aperture of 23 mm diameter at a distance of 8 mm from the
interaction region. The Mangin reflectors are aluminum coated with reflectivity of 0.9.
In addition to the primary and secondary detection systems, the UHSAS has a reference detector.
This detector serves as a reference for changes in laser power.
The Mechanical Housing
The laser and detection optics are built into the optical block, which is a sealed mechanical
enclosure. See the following figures.

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Figure 5: Light Collection Angles
Figure 4 and Figure 5 show two views of the optical cavity. Figure 4 shows the general layout of the
aerosol inlet, placement of the solid state laser and particle stream with respect to the mangin
mirror pair.
Figure 5 shows the optical path of light collected from scattering by particles that pass through the
laser. The detector is located at 900to the path of the particle through the laser. (The laser can be
Figure 4: Side View of Optical Block

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envisioned as shining into the page.) The mangin mirror pair collects the scattered light over solid
angles of 900± 570(330–1470), excluding the angles subtended by the circular opening of the
mangin mirrors 900± 14.80(75.20–104.80).
For the purpose of calculating scattering cross sections with Mie scattering, the collection angles
are 330-75.20and 104.80-1470.
The Figure below shows a top view of the optical block:

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Unpacking, Setup, Installation, and Power Up
1.8 Unpacking
The SP2-XR is shipped in a case specially designed to fit and protect the contents of the shipment.
This case should be saved and used to return the instrument to DMT if service is needed.
The shipment also includes:
•Calibration Documents
•Toolkit
•Alignment Tools
•Benchtop power supply with regional adapters and aircraft power integration cable
•Zero count filter
Check all contents for damage immediately upon receipt and notify the carrier and DMT if any
damage is noted.
1.9 Installation
The SP2-XR is shipped with a benchtop power supply (including regional adapters) and an aircraft
power integration cable. If using in a laboratory setting, simply follow section 1.10 Setup to proceed.
If using in a mobile setting and/or on an aircraft, care must be taken in mounting the SP2-XR. See
Appendix G: Mounting Information to ensure that you take care to mount the SP2-XR properly.
In all cases, good practice and care must be exercised to ensure that the aerosol losses in the sampling
system are minimized; including minimizing sample tubing length, ensuring that any inlet that is used
is conductive and basic sampling theory is followed.
1.10 Setup
1. Connect the SP2-XR power cable, either remote power or the provided power supply.
2. If using the provided power supply, plug in the appropriate region’s adapter. The optional ground
is generally used to protect the instrument in an aircraft.

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Figure 4: SP2-XR Power Connections and Cables
3. There will be a plug on the inlet and exhaust tube, be sure to remove it before powering up the
instrument.
NOTE: The SP2-XR computer is intended for running the software for the SP2-XR instrument.
Installing and running additional programs on the computer, including Anti-Virus software, may
compromise the performance of the system.
WARNING: If not properly grounded, the instrument can cause an electrical shock. Use a
three-conductor cord and a plug appropriate for the location in which the instrument will
be used. Connect the plug to a properly grounded receptacle. Be sure to use power-surge
protection for your instrument.
4. Power-up the SP2-XR using the System Power switch located on the front panel.
Figure 5: SP2-XR Power Switch
5. Start the SP2-XR software by double-clicking the SP2-XR icon on desktop.
6. In the software, go to the Actions dropdown menu in the upper left-hand corner of the screen (A)
or use the indicator buttons (B)(Figure 6).
Power supply and cord
Optional ground
Aircraft
power cable
Fuse drawer

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7. Click Start Pump and wait until the pump can be heard running.
WARNING:Pump must be activated before the laser is turned on.
8. Once the pump has started and the sheath air and sample flows are stable, it is safe to toggle the
Laser On.
NOTE: If the Laser is on and the pump has been turned off, the pump will be prevented from being
re-activated until the laser is turned off. Turn off the laser then the pump can be activated.
CAUTION: Make sure the case fans (front panel), and laser cooling fan (underneath) have
adequate ventilation. Failure to do so may result in damage to the instrument.
Figure 6: SP2-XR Screen with Actions Tab
1.11 Powering the System Down
1. On the SP2-XR software’s Actions tab (Figure 6) toggle Laser Off.
WARNING:Laser Power must be turned off before the pump is turned off.
2. Click Stop Pump.
3. Shut down the SP2-XR software by selecting File > Exit.
A
B