“The unparalleled sensitivity of the SP2 has allowed us to investigate black carbon in the polar ice caps at a previously unimaginable temporal resolution. The instrument has opened up a whole new area of research with respect to black carbon in the Earth system.”
— Ross Edwards, Senior Research Fellow, Curtin University of Technology, Perth, Australia
Click here for a video of the SP2 being used for ice core sampling.
The SP2's high sensitivity, fast response, and specificity to elemental carbon make it the premier instrument for characterizing air pollution sources and documenting thin atmospheric layers of contamination. It is also ideal for measuring soot in snow, ice or water and for calibrating other black carbon-measuring instruments like the Aethalometer.
DMT recently released version D of the SP2. The instrument now features an i7 processor with 8GB RAM. This more powerful computer allows the SP2 to measure much higher particle concentrations. It will not lose particles until particles become coincident. Other new features are listed below.
The SP2 comes with a software program that provides a user-friendly virtual instrument panel for the control, data display, and data logging of the SP2 instrument. For instance, the program enables the user to do the following tasks:
The SP2 also comes with a free copy of the Probe Analysis Package for Igor (PAPI). This program facilitates SP2 data analysis in several ways:
Click here for a video overview of PAPI.
The SP2 uses the high optical power available intra-cavity from an Nd:YAG laser. Light-absorbing particles containing mainly black or elemental carbon absorb energy and are heated to the point of incandescence. The incandescent emission is measured and correlated to the particle’s black carbon mass with the help of black carbon proxies like Aquadag or fullerene soot.
The SP2 also includes a scattering detector, which detects single-particle light-scattering at 1064 nm. The scattering signal can be used to indicate particle size and the black carbon mixing state at the single-particle level. The scattering detector can also be used to detect non-BC-containing aerosol number and mass concentrations.
The full scattering and/or incandescence response of each particle is completely digitized for detailed analysis.
|Measured Parameters||Single-particle laser incandescence
Single-particle light scattering
|Derived Parameters||BC mass distribution as function of particle diameter
Particle number distribution as a function of particle size
|Maximum Data Acquisition Rate||0 – 12,500 particles/cm3 at 120 vccm (0 - 25,000 particles/sec; concentrations can basically increase until particles become coincident)|
|Particle Size Range||
Scattering signal: 200 – 430 nm diameter (this range encompasses the accumulation mode of most particles, i.e. range where most mass is found); range can be extended to 700 nm using software post-processing of saturated signals.
Incandescent signal: depends on particle density, but 70 – 500 nm mass-equivalent diameter assuming a black carbon density of 1.8 g/cm3
|Aerosol Medium||Air, 0 - 40 °C (32 - 104 °F)|
|Lasers||Nd:YAG Laser: 1064 nm, 3 MW/cm2 intracavity circulating power
Pump Laser: 808 nm, 4 W
The pump laser can be controlled either through the SP2 software or through the touch-screen on the SP2 front panel.)
|Sample Flow||30 – 180 volumetric cm3/minute (typically 120)|
|Flow Control||Electronic flow control with a laminar flow element (LFE) and a solenoid valve|
|Pump||Two single-head diaphragm pumps encased in a box|
|Minimum Black Carbon Detection Limit||
|Calibration||DMT recommends calibrating the SP2 every six months and/or before and after every field campaign.
Monthly and around field campaigns:
Annually (more frequently for high-BC environments):
|Recommended Service||Annual cleaning and calibration at DMT service facility|
|Front Panel Display||
|Rear Panel Connections||
|Software||SP2 Executable program written in LabVIEW
PAPI program written in Igor
|Data Storage Capacity||Depends on number of particles; at a concentration of 1,000 #/cm3 and a standard flow rate of 120 volumetric cm3/minute, the SP2 computer has the capacity to store 56 hours of continuous data|
|Communications Output||Gigabyte Ethernet interfaced through an Intel® PC82573V PCIe GbE controller|
SP2: Universal Voltage
External Pump: 30 W
SP2: 48 cm W x 61 cm L x 26 cm H
Pump: 20 cm W x 25 cm L x 10 cm H
19" Monitor: 37 cm W x 22 cm L x 39 cm H
SP2: 26.1 kg
Pump: 3.4 kg
19" Monitor: 3 kg
|Shipping Container||Durable Atlas Case Corporation ATA Transit Case that conforms to the Air Transport Association’s Specification 300 Category 1 standards|
|Environmental Operating Conditions||
Temperature: 0 – 40°C (32 – 104 °F)
RH: 0 – 100% RH non-condensing
Specifications are subject to change without notice. The SP2 is a Class I Laser Product with U.S. Patent # 5,920,388, exclusively licensed to DMT.
SP2 software versions 4.2 and later are compatible with the U5000AT+ Ultrasonic Nebulizer from CETAC Technologies. The nebulizer is ideal for testing black carbon in liquid samples.
Contact DMT for pricing or more information.
Phone: +001 303 440 5576
Stephens, M., N. Turner, and J. Sandberg, “Particle identification by laser-induced incandescence in a solid-state laser cavity,” Applied Optics, 42 (19), 3726-3736, 2003. Link
Slowik, J. G., E. S. Cross, J. -H. Han, P. Davidovits, T. B. Onasch, J. T. Jayne, L. R. Williams, M. R. Canagaratna, D. R. Worsnop, R. K. Chakrabarty, H. Moosmüller, W. P. Arnott, J. P. Schwarz, R. S. Gao, D. W. Fahey, G. L. Kok, and A. Petzold, “An inter-comparison of instruments measuring black carbon content of soot particles,” Aerosol Science and Technology, 41, 295-314, 2007. (1 Mar 2007)Link
Baumgardner, D., G. L. Kok, and G. B. Raga, “On the diurnal variability of particle properties related to light absorbing carbon in Mexico City,” Atmospheric Chemistry and Physics, 7, 2517-2526, 2007. (14 May 2007)Link
McConnell, J., R. Edwards, G. Kok, M. Flanner, C. Zender, E. Saltzman, J. Banta, D. Pasteris, M. Carter, J. Kahl, “20th-Century Industrial Black Carbon Emissions Altered Arctic Climate Forcing,” Science, 317, 1381-1384, 2007.Link
Moteki, N., Y. Kondo, Y. Miyazaki, N. Takegawa, Y. Komazaki, G. Kurata, T. Shirai, D. R. Blake, T. Miyakawa, and M. Koike, “Evolution of the mixing state of black carbon particles: Aircraft measurements over the western Pacific in March 2004,” Geophysical Research Letters, 34, doi:10.1029/2006GL028943, 2007. Link
Subramanian, R., G. L. Kok, D. Baumgardner, A. Clarke, Y. Shinozuka, T. L. Campos, C. G. Heizer, and B. B. Stephens, “Black carbon over Mexico: the effect of atmospheric transport on mixing state, mass absorption cross-section, and BC/CO ratios,” Atmospheric Chemistry and Physics, 10, 219-237, 2010. (20 October 2009) Link
Bisiaux, M., R. Edwards, A. C. Heyvaert, J. M. Thomas, B. Fitzgerald, R. B. Susfalk, S. G. Schladow, and M. Thaw. “Stormwater and Fire as Sources of Black Carbon Nanoparticles to Lake Tahoe.” Environmental Science & Technology. Feb 2011. Link
Click here for a comprehensive list of SP2-related publications.