SOOTSCAN™ MODEL OT21 OPTICAL TRANSMISSOMETER

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SOOTSCAN™ MODEL OT21

The SootScan™ Model OT21 Optical Transmissometer bench top analyzer is a simple and robust instrument which measures the Black Carbon content of an aerosol sample collected on a filter, either from  ambient air or from source emissions.

The SootScan™ Model OT21 Optical Transmissometer can analyze aerosol samples quickly and easily in the field or the laboratory, to determine optical attenuation and BC / BrC mass results.  The analysis is performed at two wavelengths (880 nm, definitive for “Black” Carbon; and 370 nm, where enhanced optical absorption may indicate the presence of “Brown” Carbon aerosol derived from biomass combustion.)

The analysis is non-contact, non-contaminating and non-destructive.  It may therefore be performed before other laboratory techniques are applied to the sample.  The analysis method requires no support gases or consumables.  A neutral density photometric standard kit is available for verifying instrument calibration and validating the instrument response.

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PRODUCT INFO

The SootScan™ Model OT21 Optical Transmissometer bench top analyzer has been developed as a simple and robust way of measuring the Black Carbon content of particulate matter (PM) collected on sample filters.  The analysis can be easily performed in the field or the laboratory, and provides optical attenuation and BC mass results in only a few seconds.  The analysis is non-contact, non-contaminating and non-destructive.  It may therefore be performed before other laboratory techniques are applied to the sample.  It requires no support gases or consumables.  A neutral density photometric standard kit is available for verifying instrument calibration and validating the instrument response.

METHOD

Since the method does not alter, contaminate or destroy the sample during analysis, the OT21 can be used to quickly determine BC from samples collected specifically for US EPA PM-2.5 Federal Reference Method (FRM), Method 5 / 201A stationary source and mobile source compliance determination.

Importantly, because Black Carbon is a non-volatile component of particulate matter, the analysis can be performed not only on freshly collected samples, but also on historically archived filters in order to detect long-term trends.

APPROACH

The instrument contains a 2 wavelength light source: 880 nm providing the quantitative measurement of Black Carbon PM and a 370 nm for qualitative assessment of certain aromatic organic compounds, often described as ‘Brown Carbon’ and usually associated with biomass combustion emissions.

This 2-wavelength data provides additional information which is important for determining:

  • source apportionment of ambient PM samples (i.e. wood smoke vs. diesel PM) or
  • the mechanical status of an internal-combustion engine (i.e. black smoke = poor combustion efficiency, fuel system needs adjustment; blue smoke = mechanical wear, oil entering combustion chamber).

FILTERS

The instrument is supplied with sample holders which accept 15, 25, 37, or 47mm diameter filters comprised of Teflon, quartz fiber, glass fiber, or Teflon-coated glass fiber media.  Punches may be taken of samples collected on large-size filters (e.g.. 8 x 10″ high volume filter or 70mm or larger source sample filter).

SPECIFICATIONS

The SootScan™ Model OT21 Optical Transmissometer allows users to measure and record filter absorbance data relative to a blank reference filter.
These results can be interpreted in terms of the surface loading of particulate material collected on the filter, to provide an analysis of the composition of the sample.  As a stand-alone system, the OT21 measures absorbance data at both ultraviolet (370nm) and infrared (880nm) wavelengths.

Operation

  • Supply voltage: 100-240 VAC, 50/60 Hz
  • Max power consumption: 15W
  • Measurement wavelengths: 370 nm and 880 nm

Environmental operating conditions

  • Indoor use only
  • Altitude: up to 3000 m
  • Temperature range: 10 – 40 degrees Celsius (instrument)
  • Relative humidity range: 10 – 95 %

Mechanical specification

  • Chassis: metal enclosure with aluminium alloy end panels: black anodized / powder coated.
  • Dimensions: 320 mm x 130 mm x 295 mm
  • Weight: 5,5 kg

Connectors

  • Filter tray
  • Data Communication: USB-typeB, COM (DB9)

User interface

  • 2x20 characters display
  • 4-button keypad
  • Beeper

DOCUMENTS

TitleTypeDownload
Magee Scientific SootScan OT21 Transmissometer brochure sheet A4BROCHURE SHEETDownload
Frank (NAMC 2009) Optical Analysis of FRM filtersPRESENTATIONDownload
Magee Scientific Sootscan OT 21 Optical Analysis of Standards for Validation and CalibrationWHITEPAPERDownload
Hu (2011) Real-time and filter-based BC measurements for vehicle emissionsPOSTERDownload
First measurements of aerosol black carbon in a very humid areaPRESENTATIONDownload

PUBLICATIONS

TitleAuthorPublicationYearLink
Filter Light Attenuation as a Surrogate for Elemental CarbonJudith C. ChowJournal of the Air & Waste Management Association
Volume 60, 2010 - Issue 11
2012Link
Measurement of black carbon (BC) by an optical method and a thermal-optical method: Intercomparison for four sitesTanveerAhmedVolume 43, Issue 40, December 2009, Pages 6305-63112009Link
Gundel (1984) ATN vs BC - SciTotEnvGundelPrinted in the Netherlands1984Download

ACCESSORIES

We offer accessories and routine supplies as shown below.  Please inquire with our sales team about your specific needs.

NEUTRAL DENSITY OPTICAL VALIDATION KIT

The Neutral Density Optical Kit provides a validation of the reproducibility of the photometric detectors.
The reproducibility of the optical attenuation method employed by the SootScan™ Model OT21 Optical Transmissometer may be validated by the use of the Neutral Density Optical Kit.  This kit consists of elements of Neutral Density optical glass, with stable optical absorbances that may be referenced back to traceable photometric standards.  The kit is used to verify that the optical performance of the instrument is constant with time, relative to its original manufacturing certification.

SMALL HOLE FILTER ADAPTER

Additional filter adapter for small area analysis (10 mm center, 14 mm outer diameter).

ARC PUNCHER

Arc puncher 25 mm for punching out sampled filters (for further analysis).

OT21 software – latest release and other important documents

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