Sigma Scientifics Positive Pressure CADS Units: deliver a reference standard controlled air supply for olfactometry and push volatile collection Bioassay systems.  These CADS units are available in 2-Port and 4-Port configurations.

 

Pressurized supply air (Please do not to exceed 100 PSI) enters the back of the unit via a ¼” OD Swagelok tube fitting or an industrial quick disconnect. The dual mini air filter on the rear of the Clean Air Delivery System (CADS) removes liquid water and solid particulates from air lines, extending the life of your CADS.  

 

It is the first stage for filtration of the CADS unit. With a 40 micron particle filtration, these mini air filters feature a durable polycarbonate reservoir able to withstand heavy daily use. The pressurized air is cleansed of both liquid and solid particulates. This is accomplished first by cyclonic action then a coalescing section and finally a sintered filtration.  If excessive water is collected in the mini filter a purge valve is opened by pushing up on the bottom tip.  A minimum pressure of 30 PSI is required to seal the release valve during operation.  The release valve automatically opens when the system is depressurized.  A short rubber tube with 3/16 inside diameter can be attached to the release valve to drain any accumulated water to a specific location.  

 

The particulate free air then encounters a high pressure gauge for monitoring the supply pressure (0 – 160 PSI.)  The air next enters a pressure regulator with gauge allowing for adjustment of the air pressure to the operating parameters for the experiment, Sigma suggests an operating pressure of 15 psi.   

 

 The air now enters a distribution manifold for an even, non-fluctuating source of air for entree to the selected ports. Every port has a dedicated five element final scrubbing cartridge the main component consisting of acid washed granular activated carbon to ensure organic matter removal.  See our white paper on Sigma Clean Air Filters for details on the filter cartridges.  The cap and body are spin-welded together producing a smooth, consistent seal without glues or binders that can cause contamination. Swagelok™ ¼” tubing connectors are used for all internal connections.    

 

Upon port selection the processed air enters the inlet side of the precision flow meter where a needle valve control adjusts the air flow as indicated by a float bead (usually 0  - 3.0 LPM on a 150mm direct read scale for air) and exits the system for experimental use.  Once the flow meters are set, you may change the flow rate of all four flow meters equally by adjusting the pressure regulator.  

 

Sigma Scientific recommends an air compressor for operation of the CADS unit.  Compressed air is normally high in relative humidity (90 – 100%)  If using house air, check with the building supervisor to determine the quality of the air.  If chillers are used to remove all humidity from house air, bubblers may be required to re-humidify the air used in experiments.  High pressure tank air can also be used for olfactometry experiments.  Contact Sigma Scientific for bubblers, high pressure tank regulators and hoses or look in our accessories section.

 

CADS-2Push2-Port Clean Air Delivery System: for use with one Y-Tube, Parallel Arm Tube, U-Tube, or any other 2-Choice Olfactometer.    System includes separate secondary filter cartridges for each channel.  CADS-2Push can be upgraded to a 4 channel system.  Approximate dimensions of CADS-2Push: is 33 cm (12 ¾ “) wide by 39 cm (15 5/16 “) Tall by 30 cm (11 ¾ “) depth.  System comes with standard quick disconnect for air source and two ¼” Swagelok™ tube connectors on front for air delivery.        

 

CADS-4Push 4-Port Clean Air Delivery System: for use with two: Y-Tubes, Wishbone Tubes, U-Tubes, or any other 4-Choice Olfactometer.  Four separate secondary filter cartridges, one for each channel. (NOTE: A stand alone precision 0-6 LPM, 150mm direct read vacuum flow meter is required for use with a 4-Choice Arena Olfactometer and must be purchased separately.)     Approximate dimensions of CADS:  33 cm (12 ¾ “) wide by 39 cm (15 5/16 “) Tall by 30 cm (11 ¾ “) depth.  System comes with standard quick disconnect for air source and four ¼” Swagelok™ tube connectors for output of clean air.    

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