SASS 3100R Dry Filter Aerosol Sampler - resrchintl.com · SASS 3100/3100R• December, 2013 •...
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Transcript of SASS 3100R Dry Filter Aerosol Sampler - resrchintl.com · SASS 3100/3100R• December, 2013 •...
SASS 3100/3100R• December, 2013 • Page 2
Dry samplers have favorable properties: – Organisms maintain their original state; wet sampling
causes a fundamental change in environment – A dry collection strategy means no water needs to be
carried or stored; – Water freezing is not a concern- the operating
temperature range can be expanded; – Dry samplers tend to be simpler in design, more reliable
and more compact, longer running and more easily decontaminated.
However, collected materials must be extracted in a second step
SASS® 3100R Dry Sampler
SASS 3100/3100R• December, 2013 • Page 3
SASS 3100R Dry Air Sampler
Lightweight and portable- 2.8 kg w/bat. 24-hour operation on battery power Microprocessor in sampler allows either biological or radiological filter to be used over a range of sampling rates. Collection efficiency for biological filter:
- 0.5 µm dia: 50% - 1.0 µm dia: 75% - 2.0 µm >dia: 90%
Collection efficiency for radiological: >99% for >0.3 microns dia. Operable from -40C to 70C Programmable/digitally controllable SASS 3100 Top performer out of 10 competitors at 2008 TRE 08-2; top contender for U.S. JBTDS program.
SASS 3100/3100R• December, 2013 • Page 5
The biological electret filter is designed to optimize conversion of electrical energy to pressure-volume pneumatic energy
This maximizes sampled air volume and operating time on battery power- the 3100R sampler offers unusually high performance in a small long-running portable format.
SASS® 3100 System Optimization
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SASS 3000 operating point
SASS 3100/3100R• December, 2013 • Page 6
The 3100R sampler can be programmed from a PC to automatically perform multi-step protocols
Features that can be modified include: – Delay before sampling – Sampling time – Delay between sampling periods – Number of sampling periods. – Sampling flow rate
When downloaded to the sampler, it will execute the feature set on all future runs until the protocol is changed.
The sampler can also be turned on and off remotely by wireless or RS-232 commands
Software Modifiable Operation
SASS 3100/3100R• December, 2013 • Page 7
SASS 3100R Proprietary Filters
RI’s biological filter media has an extremely high efficiency coupled with a pressure drop that is 5% of a comparable conventional filter.
Both filter media are fibrous ‘electret’ materials – A complex electric field emanates from each
polypropylene filter fiber; – ‘Action-at-a-distance’ electrostatic attraction
draws aerosols to the fibers; – Electrostatic forces cause captured aerosols
to cling tightly to each filter’s fibrous matrix – Can withstand prolonged water immersion; – Stable for a decade or more; – Will withstand temperatures to 700C; – 43 mm nominal active diameter
Portable samplers based on these filters exceed all others in collection ability, small system size, temperature range and operating life
SASS 3100/3100R• December, 2013 • Page 8
The felt-like polypropylene electret material is mounted in a polypropylene frame using one of two placement methods: – Sonic welding; or – A friction-lock approach wherein the
filter “biscuit” is sandwiched between the frame and an annular backing scrim
The latter is convenient for forensic applications since the biscuit can be removed with tweezers for analysis.
The filter assembly is mounted onto the sampler by pressing and friction-locking it onto an inlet boss. There is no inlet ducting to become contaminated.
Contamination by previous test residues is minimized.
Filter Assemblies
SASS 3100/3100R• December, 2013 • Page 9
Comparable paper filters for radioactive aerosol collection have extremely high pressure drops and often need to be used with a vacuum pump to create an adequate air flow.
RI’s electrostatic filters coupled with the SASS 3100R blower provide an unprecedented range of field opportunities never before possible in the radioactive aerosol collection field: – 24 hour unattended operation – Remote control and programmability – Small size and quiet operation
Very low radiative self-absorption- 2.2 mg/cm2 mass/area is only 25% of the areal density of a Whatman 41 filter.
Of course, the filter is also useable for biological aerosols
Comments on the Radioactive Aerosol Filter
SASS 3100/3100R• December, 2013 • Page 10
The exceptionally strong electrostatic holding forces also provide a challenge if the particles need to be removed from the filter for analysis.
Research International has developed a small manual ‘extracting machine’ and a preferred extraction fluid formula to efficiently remove particulates.
Efficiencies of 60-80% are typical.
Alternatively, the biscuits will also fit many standard 50mm paper filter holders
Typical radioactive material assays do not require particulate extraction- measurements are made directly from the filter.
Extracting Particulates
SASS 3100/3100R• December, 2013 • Page 11
SASS 3010 Manual Particle Extractor
Extracts particulates from the electret filters used with SASS 3100R or SASS 4100;
A 4 to 10 ml charge of extraction fluid is added from a 16 ml dropper bottle
Sonic agitation dislodges particulates from the fibrous matrix
The extracted sample is discharged into the dropper bottle; use with HHA’s or any wet bioanalyzer
1 minute process time 60-80% efficiency Supported in DoD technology upgrade program
(JBTDS application) U.S. Patents 8,057,608 and 8,142,570
SASS 3100/3100R• December, 2013 • Page 12
Extraction Efficiency Vs. Extraction Fluid Volume
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Extraction efficiency is essentially constant as long as the fluid sample exceeds 4 ml
SASS 3100/3100R• December, 2013 • Page 13
The samplers are easy to service and decontaminate.
The volute surrounding the fan rotor is detachable by removing three finger screws. It can be directly immersed in bleach or other decontaminating solution.
The fan rotor may be bleach decontaminated by turning the unit upside down and immersing the rotor assembly in bleach. Turning the unit on after removal from the bleach will spin dry residual fluid on the rotor and minimize corrosion.
The entire rotor assembly can be replaced by removing 4 screws and disconnecting an electrical connector.
SASS® 3100R Decontamination
SASS 3100/3100R• December, 2013 • Page 14
Research International, Inc.
17161 Beaton Road SE Monroe, WA 98272-1034
Phone: 360-805-4930 • Toll Free: 1-800-927-7831 www.resrchintl.com • [email protected]