CARBONACEOUS AEROSOL SPECIATION SYSTEM CASS

CASS delivers advanced, comprehensive carbonaceous aerosol measurements by integrating real‑time thermal and multi‑wavelength optical analysis within a single system, combining the TCA09 Total Carbon Analyzer with the Aethalometer AE36 or AE36s.

1. Black carbon from liquid fuels (BC_LF)
2. Black carbon from solid fuels (BC_SF)
3. Primary organic carbon from liquid fuels (POC_LF)
4. Primary organic carbon from solid fuels (POC_SF)
5. Secondary organic carbon (SOC)

These results are reported in real time and visualised directly on the screen, using multiple chart formats to provide immediate insight into source contributions and temporal dynamics.

By incorporating a 2D BC tracer, this model enables source identification and characterization of carbonaceous aerosol composition, supporting detailed interpretation of emission sources and atmospheric processing relevant to air quality, climate, and health studies.

Leveraging the combined strengths of the AE36 or AE36s and the TCA09, CASS delivers high-resolution, source-resolved data with automated calibration, artifact correction, and robust validation.

This enables precise quantification and apportionment of carbonaceous aerosols, supporting detailed air quality assessments, climate research, and regulatory compliance with minimal maintenance and maximum operational efficiency. 

CASS delivers advanced measurement capabilities with high time resolution and real-time data.

This enables the capture of dynamic changes in carbonaceous aerosol concentrations on a 10-minute time scale.

As a result, users gain immediate, actionable insights into air quality and emission events, supporting advanced research, regulatory monitoring, and timely decision-making.

CASS features fully automated calibration and validation processes, ensuring that every measurement is accurate, reliable, and traceable. By integrating automated calibration routines, such as sucrose-based carbon constant calibration and VOC artifact correction, with continuous system validation, CASS minimizes manual interventions and reduces the risk of human error. This robust automation streamlines routine operation and guarantees consistent data quality, supporting regulatory compliance and advanced scientific research with confidence.

CASS requires low maintenance and is constructed for robust operation, combining automated calibration, self-maintaining procedures, and extended filter life to minimize manual interventions.

Its durable construction and advanced diagnostic features ensure reliable performance even in challenging environments, while continuous data validation and artifact correction maintain high data quality. This makes CASS ideal for long-term, unattended monitoring and demanding research applications, providing users with dependable, high-quality results and peace of mind.

CASS features a user-friendly and safe design, prioritizing ease of use and operator protection. Its intuitive graphical interface streamlines instrument setup, operation, and data visualization, making advanced aerosol analysis accessible to both experts and new users. Safety is enhanced through features such as an electronic lock, which prevents access to high-temperature components during operation, and secure connections with Swagelok tubes. This thoughtful design ensures reliable performance while minimizing risks, supporting safe and efficient deployment in diverse research and monitoring environments.

CASS offers flexible deployment, making it suitable for a wide range of monitoring scenarios, from stationary air quality stations to field campaigns in special enclosures. Its compact, modular design and compatibility with existing infrastructure, such as predecessor inlet tubes, allow for easy integration and rapid setup in diverse environments. Whether used for long-term unattended operation or dynamic research projects, CASS adapts seamlessly to the needs of laboratories, regulatory agencies, and scientific teams, ensuring reliable performance wherever comprehensive carbonaceous aerosol analysis is required.

The Carbonaceous Aerosol Speciation System (CASS) is available in two variants, based on either the Aethalometer AE36 or the Aethalometer AE36s, both integrated with the Total Carbon Analyzer TCA09. While the overall CASS workflow remains the same, each configuration reflects the specific capabilities of its core instruments. For full technical highlights, specifications, and feature details, please refer to the dedicated product pages:

• Aethalometer AE36
• Aethalometer AE36s
• Total Carbon Analyzer TCA09

Carbonaceous Aerosol Fingerprint, a 6‑component model (CAF₆), is the most advanced analytical model that can be used with CASS data. It provides a high‑resolution fingerprint of carbonaceous aerosols, resolving both light‑absorbing and non‑absorbing components and distinguishing between primary and secondary fractions.

CAF₆ apportions carbonaceous aerosol into six physically and chemically meaningful components:

1. Black carbon from liquid fuels (traffic)
2. Black carbon from solid fuels (biomass burning)
3. Primary non‑absorbing organic aerosol
4. Secondary non‑absorbing organic aerosol
5. Primary brown carbon
6. Secondary brown carbon

This structure goes beyond simpler, yet more robust BC/OC separation (5‑component total carbon apportionment model – TCAM₅) by explicitly accounting for brown carbon (BrC) and for atmospheric aging and secondary formation processes. The result is a detailed, time‑resolved aerosol composition that links emissions, transformation, and optical properties in a single framework.

CAF₆ should be applied when high‑quality multi‑wavelength optical data are available and when the measured aerosol includes a meaningful contribution from biomass burning or aged organic aerosol. In environments dominated by traffic emissions with negligible brown carbon, simpler model TCAM₅ is scientifically more appropriate.

Refer to this application for more details.

CASS is a combination of Aethalometer and Total Carbon Analyzer.

MEASUREMENT PRINCIPLE

Optical Analysis of BC with continuous collection of aerosol on filter and simultaneous measurement of attenuation of transmitted light at wavelengths from UV to IR wavelength range.

Thermal Analysis of TC with flash-heating of sample collected on a quartz filter to convert all Carbon to CO2. The mathematical principle is simple:

Total Carbon (TC) = Black (or Elemental) Carbon (BC, EC) + Organic Carbon (OC):

• Measure TC with the TCA09
• Measure BC/EC with the Aethalometer®
• Derive OC in near-Real Time: OC = TC – EC.

The Aethalometer® also identifies ‘Brown
Carbon’ (BrC) by multi-wavelength optical analysis, and also separates Biomass Smoke from Diesel Emissions.

SPECIFIED PERFORMANCE OF AE36 or AE36s

• Sensitivity: Proportional to time-base and sample flow rate settings: <10 ng/m3 @ 1 min, 5 LPM
• Detection limit of BC (1 hour) <0.001 μg/m3
• Detection range of BC: <0.01 to >100 μg/m3

SPECIFIED  PERFORMANCE OF TCA09

• Limit of Detection: 100 ng C/m³ (1 h timebase, 16.7 LPM flow)
• Range: 100 ng C/m3 to 1,000,000 ng C/m3 of Total Carbon (1 h timebase, 16.7 LPM flow)

AE36 or AE36s sampling flow rate of BC/EC adjustable from 2 to 5 LPM, provided by closed-loop stabilized internal pump and two mass flow sensors.

Sampling flow rate for TCA09 of 16.7 SLPM (1 m3/h),
provided by closed-loop stabilized internal pump.

Automatic or manual sample flow rate calibration using an externally attached calibrator. Validation of optical performance using kit of neutral density filters.
Pre-programmed built-in zero air test – clean air test for TC and BC.

DISPLAY

10.1” color touch-screens with status indicator LED’s

INTERFACE

Graphical User Interface with basic data display and control, advanced screens for detailed reporting and parameter setup.

REMOTE MANAGEMENT

Network ready for remote management and data transfer.

• Indoor or laboratory use, rack or benchtop
• Temperature: from 5°C – 45°C
• Humidity: 5 % – 95 %, non-condensing
• Operating altitude: 0 ~ 3000 m.
• Input / output connections:
  • Sampling air inlet: Stainless Steel Swagelok Tube Fitting, Union, 1/2 inch Tube OD
  • Sampling air outlet: standard ¼” NTPF threaded connector
  • Analytical carrier air inlet: standard ¼” NTPF threaded connector

DATA OUTPUT

Digital data via RS-232 COM port and Ethernet. Network ready for remote management and data
transfer.

STORAGE

Data are written to internal memory once every timebase period. Stored data may be transferred over a network or to a manually inserted USB drive.

• Constructed in standard 19″ rack-mount chassis.
• Dimensions (H x W x D): 52 x 48 x 52 cm (20” x 19” x 20”)
• Weight: 74 kg (163 lbs)
• Electrical supply: 100-240 VAC, Voltage range: 85- 264 V AC, 50/60 Hz
• Power consumption (maximum): max 1200 W; typical 100 W
• Internal sampling pump: dual diaphragm, brushless speed-controlled DC motor, stabilized flow.
• Modular internal hardware for rapid servicing.
• Constructed in fully-enclosed, self-contained rack-mount chassis.

• Very sharp cut cyclone inlet PM2.5 @ 16.7 LPM
• Sharp cut cyclone inlet PM2.5 @ 16.7 LPM
• Sharp cut cyclone inlet PM1 @ 16.7 LPM
• Shockproof and waterproof transit case
• Flow Calibrator ALICAT FP-25 (0.1-25 LPM) includes comunication cable includes comunication cable
• Ambient meteorological sensor GMX 300 (P, T, RH)
• Ambient meteorological sensor GMX 200 (wind speed and direction)
• Ambient meteorological sensor GMX 500 (P, T, RH, wind speed and direction)
• Sample inlet direct vertical installation for TCA09
• Inlet installation kit
• Sampling tube insulation
• Insect and water trap assembly
• Swagelock sampling tubing (various length) with different adapters
• Air splitter
• Neutral density optical filter validation kit
• Ambient meteorological sensor
• Wind speed and direction sensor
• Sample Stream Dryer
• PM2.5 Inlet (2.5 μm @ 5 LPM)
• PM1 Inlet (1 μm @ 5 LPM, 2.5 um @ 2 LPM)
• Insect screen assembly with water trap
• Tape sensor calibration disc kit
• GPS module
• External pump for High-Altitude operation