The Wideband Integrated Bioaerosol Sensor (WIBS-NEO)

 
The WIBS-NEO is the newest generation of bioaerosol instrumentation and provides detailed information on atmospheric bacteria, molds, pollen and other bioaerosols. The three UV wavebands have been selected to optimize detection of common bioaerosols (tryptophan and NADH).

 

Applications

  • Bioaerosol research (mold, pollen, fungi)
  • Air quality studies
  • Health effects research

 

Advantages

The WIBS-NEO offers many advantages:

The WIBS-NEO provides highly sensitive measurements of mold and other bioaerosols. The instrument uses a UV xenon source to excite fluorescence in individual particles. Unlike UV lasers, the UV xenon source allows for the precise selection of particular UV wavebands.

The instrument's standard wavebands have been selected to optimize detection of the common bioaerosol components tryptophan and NADH. However, users can order the WIBS-NEO with customized wavelengths for both excitation and emissions measurement.
The WIBS-NEO provides particle-by-particle data. It also supplies particle time-of-flight to detect coincidence. A special mode is available to measure larger particles such as pollens and fungal spores.

In addition to particle measurement data, the WIBS-NEO records data on instrument health.
The user can select filter criteria for both full and partial measurements. Data may be filtered using a wide variety of criteria: particle size, asymmetry, and concentration; fluorescent excitation and emission; or ratios of any of these parameters.
The WIBS-NEO is suitable for airborne or ground-based sampling.
The WIBS's xenon source is far less expensive than a UV laser, making the WIBS-NEO a cost-effective alternative to other bioaerosol measurement instruments

 

Software

Two software packages are available for the WIBS, the standard software system and the WIBS Data Analysis Toolkit.

Standard Software

The WIBS-NEO graphical user interface features several components. The main window shown below details measured particles in real time and gives information on several housekeeping parameters. 

 

WIBS Data Analysis Toolkit

The WIBS toolkit allows for loading, processing and inspection of data generated by the WIBS-NEO. The toolkit's functionality includes the following:

  • Loading single and multiple raw data files containing particle-by-particle fluorescence, size, asymmetry factor and other data
  • Converting particle-by-particle data into time-resolved particle concentrations and size distributions
  • Basic plotting capability



The toolkit window is shown at right.

Online Toolkit Help System

 

 

How It Works

A laminar-flow system arranges particles in single file. The particles are drawn through the path of 635 nm diode laser, which scatters light in all directions. The forward-scattered light is used to determine particle shape. Side-scattered light is collected, passed through a dichroic beam-splitter, and converted to electrical pulses. These pulses then trigger the first xenon flash tube, Xe1, at 280 nm. The resulting fluorescence emission is collected, filtered, and passed to two fluorescent detectors, F1 and F2. The Xe2 xenon flash tube then fires at 370 nm. The resulting fluorescence emission is again collected, filtered, and passed to F1 and F2.

The WIBS thus creates a 2x2 excitation-emission matrix for each particle. This results in three fluorescent measurements. (The Xe2/F1 measurement is ignored, as the F1 detector becomes saturated with elastically scattered UV light.) The Xe1/F1 measurement is highly sensitive to tryptophan, while the F2 measurements are responsive to NADH.

The entire measurement cycle for each particle takes approximately 25 μs.

 

Specifications

Parameter Specification
Maximum Concentration 3,000 particles/L for full measurement (10% coincidence)
10,000 particles/L for sizing and counting (10% coincidence
Flourescence Excitation 280 nm, 370 nm
Flourescence Emission 310-400 nm, 420-650 nm
Flow Rate Sample: 0.3 L/min
Particle Size Range 0.5 to 50 um
Sheath 2.1 L/min
Power Reqiurements 100W, 90-230 VAC or 24 VDC at 3.0A
Weight 27.5 lbs
Dimensions 17.75"W x 14.25"L x 9.5"H (add 2" for inlet at top)

Specifications are subject to change without notice.

The WIBS was developed by Paul Kaye at the University of Hertfordshire, U.K., and is licensed by Droplet Measurement Technologies.

 

Included Items

  • Analytical Instrument
  • Internal Computer
  • Software
  • Shipping case
  • One-year warranty
  • Software toolkit for data analysis

How to Order

Contact DMT for pricing or more information.

Email: customer-contact@dropletmeasurement.com

Phone: +001 303 440 5576
Fax: +001 303 440 1965

 

Selected Bibliography

D. Baumgardner, K. McCabe, G. Kok, G. Granger, and M. Hernandez. "Using Real-Time Multiband Fluorescence Signatures to Discriminate between Bioaerosol Classes" (3.5 MB): A presentation given October 3, 2103 at the AAAR Conference in Portland, Oregon. ​PDF link (3.5 MB)

E. Toprak and M. Schnaiter, “Fluorescent biological aerosol particles (FBAPs) measured with the Waveband Integrated Bioaerosol Sensor WIBS-4: laboratory tests combined with a one year field study.” Atmos. Chem Phys. Discuss., 12, 17607–17656, 2012.Link

C. Pohlker, J.A. Huffman, and U. Poschl, “Autofluorescence of atmospheric bioaerosols-fluorescent biomolecules and potential interferences,” Atmos. Meas. Tech., 5. 37-71, 2012. Link

A.M. Gabey, M.W. Gallagher, et al. “Measurements and comparison of primary biological aerosol above and below a tropical forest canopy using a dual channel fluorescence spectrometer,” Atmos. Chem. Phys., 10, 54453-4466, 2010. Link

P. H. Kaye, J.E. Barton, et al. “Simultaneous light scattering and intrinsic fluorescence measurement for the classification of airborne particles,” Applied Optics, 39, 3738-3746, 2000. Link