Consulting
Consulting
schnaiTEC can share their experience and know-how in the following fields:
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Development of scientific instrumentation that is based on optical methods
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Instrumentation for laboratory research, e.g. cloud chamber instrumentation
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Instrumentation for field research, e.g. airborne instruments
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Particle light scattering simulations
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Expected signal of optical particle instruments, e.g. light scattering spectrometers
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Mie calculations for spherical particles
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Multiple-sphere clusters, e.g. absorption and light scattering by fractal soot particles
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T-matrix calculations for spheroidal particles
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Geometric optics for ice crystals
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Image analysis
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Processing of particle micrographs, e.g. from bright-field optical microscopy
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Extraction of microphysical properties from particle images
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Contact us for more information!
schnaiTEC can share their experience and know-how in the following fields:
-
Development of scientific instrumentation that is based on optical methods
-
Instrumentation for laboratory research, e.g. cloud chamber instrumentation
-
Instrumentation for field research, e.g. airborne instruments
-
-
Particle light scattering simulations
-
Expected signal of optical particle instruments, e.g. light scattering spectrometers
-
Mie calculations for spherical particles
-
Multiple-sphere clusters, e.g. absorption and light scattering by fractal soot particles
-
T-matrix calculations for spheroidal particles
-
Geometric optics for ice crystals
-
-
Image analysis
-
Processing of particle micrographs, e.g. from bright-field optical microscopy
-
Extraction of microphysical properties from particle images
-
Contact us for more information!
Do completely new research
Do completely new research
Hear your absorption
A direct way of measuring the aerosol absorption coefficient using the photo acoustic effect. Measurements at up to four wavelengths enable a specific characterisation of the aerosol.
Applications
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Quantification of PM1 combustion aerosol, including black and brown carbon mass concentrations
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Aerosol ageing processes under complex urban conditions
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Source apportionment studies for light absorbing particulate matter from fossil fuel and biomass burning
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Air quality monitoring networks
Features
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Detection limit better than 0.5 Mm (equivalent to a black carbon concentration (eBC) below 0.05 µg m )
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Customisable wavelength combinations in the 375 nm to 785 nm spectral range
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Separate optics, electronics, and flow units for flexible adaptation to your lab environment or implementation of accompanied measurements
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Fully integrated into 19” rack enclosures ready to be integrated in air-quality monitoring stations
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Specifications
Concept
Detection limit
Accuracy & Precision
Laser Beam
Laser Wavelengths
Acoustic resonator
Sample flow rate
Cell volume
Time resolution
Control Unit
Instrument Computer
Software
Power Consumption*
Physical Dimensions
Weight
Specific measurement of the aerosol absorption coefficient of PM1 aerosol in a single photoacoustic cell at multiple (up to four) wavelengths
0.5 Mm (approx. 0.05 µg m Black Carbon)
10% and 3%
Up to four wavelengths efficiently combined to a 0.7 mm (1/e ) collimated beam
Customisable wavelength combinations in the 375 nm to 1550 nm spectral range (e.g. 405 nm, 515 nm, 660 nm, 785 nm)
Compact stainless steel cylindrical cavity with a fundamental acoustic frequency of 3200 Hz
0.5 - 2 lpm
236 cm (including acoustic buffer volumes)
1s sampling rate. 60s typical averaging time per wavelength.
Dual core (667 MHz) real time embedded controlle
2.0 GHz CPU, 4 GB RAM, 120 GB SSD Panel PC with 8” touch screen
Graphical data acquisition software. SQL database storage for long-term monitoring
180 W typical
Optics Unit: 462 mm x 422 mm x 210 mm
Electronics Unit: 496 mm x 449 mm x 310 mm
Flow Unit: 436 mm x 449 mm x 177 mm
Optics Unit: 27 kg
Electronics Unit: 17 kg
Flow Unit: 5 kg
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Operation
Laser 1
Laser 2
Laser 3
Laser 4
lock-in amplifier
photoacoustic cell
beam dump
power measurement
aerosol in
aerosol out
Schematic diagram of the PAAS-4λ measurement setup
Sample aerosol is led through the photoacoustic cell of the instrument. This cell consists of a cylindrical cavity that has a fundamental acoustic resonance frequency of 3200 Hz...
References
Schnaiter, F. M., Linke, C., Asmi, E., Servomaa, H., Hyvärinen, A.-P., Ohata, S., Kondo, Y., and Järvinen, E.: The Four-Wavelength Photoacoustic Aerosol Absorption Spectrometer PAAS-4λ, Atmos. Meas. Tech. Discuss. [preprint], doi.org/10.5194/amt-2022-332, in review, 2023.
Schnaiter, M., Linke, C., Ibrahim, I., Kiselev, A., Waitz, F., Leisner, T., Norra, S., and Rehm, T., "Specifying the light-absorbing properties of aerosol particles in fresh snow samples, collected at the Environmental Research Station Schneefernerhaus (UFS), Zugspitze.", Atmospheric Chemistry and Physics, 19, 10829-10844, 2019, doi:10.5194/acp-19-10829-2019.
Linke, C., Ibrahim, I., Schleicher, N., Hitzenberger, R., Andreae, M. O., Leisner, T., and Schnaiter, M., "A novel single-cavity three-wavelength photoacoustic spectrometer for atmospheric aerosol research", Atmospheric Measurement Techniques, 9, 5331-3346, 2016, doi:105194/amt-9-5331-2016.