McNab Model HSA4 Cell Counter 

McNab Cell Counters

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Model HSA 4 is a photometric plus yeast analyzer for pitching, cropping, transfer and blending applications in breweries.

McNab Cell Counters provide precise yeast measurement and control by optically measuring yeast cells on the process line to facilitate pitching, cropping, transfer and blending applications.

McNab Cell Counters consist of a two-chamber flow cell assembly and indicator/controller cabinet. The flow cell assembly mounts directly in the piping of the system being monitored, and the process beer passes through its center.

Yeast content is measured at a 180o angle from the source light and is converted to an electrical signal proportional to the yeast concentration within the beer. This signal is sent to the indicator/controller cabinet.

The cabinet contains the electronic circuitry necessary to convert the signals into readings in the required units, to display these readings, to input desired set points, to indicate the alarm levels, to operate the relays, and to perform self diagnostics.

Cell Counter Applications

Yeast Pitching
To achieve accurate pitching level to fermenter, the McNab Cell Counter provides a signal (4-20mA and digital reading) in the range of 0 - 2 billion (2,000,000,000,000) cells per milliliter (range of instrument). In-pipe analysis assures pitches at target levels, for example 1.4 billion cells/mL.
Yeast Cropping
To optimize proper yeast/beer separation after fermentation, the McNab cell counter provides a signal (4-20mA and digital reading) of (0-75% of yeast volume/volume either by ASTM spin-down calibration or by hemocytometer for live cell counting.
Yeast Transfer
Plant operation is improved, yield extended and batch consistency enhanced by measuring the exact amount of yeast being transferred, for example, into and out of secondary fermentation and into and out of the centrifuge. McNab Cell Counters make an actual measure (30-55 percent solids by volume or cells/mL) of yeast cells, correlating closely with spin-down, Coulter counter and other accepted lab methods.
Yeast Blending
Where the brewmaster requires re-introduction of yeast after centrifuge or clarifying, McNab cell counters allow for the blending of clear beer and yeast to the required yeast levels, for example blending 6 to 12 million cells/mL.
Other Applications
With nearly four decades of experience in beer process monitoring and control, McNab has the capabilities to custom-design systems perfectly suited for the needs of today's breweries. McNab analyzers can be customized to control the brewing process by monitoring suspended solids concentration, particle size, clarity, chemical concentration, optical density and/or other characteristics of the in-line beer.

Diagram of Uses



Cell Counter
Principle of Operation: Direct optical measurement of yeast cell count and percent solids (spin-down), correlating to comparable optical measurements: ASBC Spin-Down (see Standard Reference Method) and cell count (Coulter counter).  The indicator analyzer receives the electrical signal proportional to cells and NIR reference.  The signals are sent to a range-defined algorithm, giving an ultra-linear signal proportional to concentration.  The signals are zeroed, scaled, and passed on to the digital meter, the auxiliary output, and also the controllers.
Measuring Range: (a) 0 - 2 million cells/mL
(b) 0 - 20 million cells/mL
(c) 0 - 0.2 (000,000,000 billion cells/mL
(d) 0 - 2 (000,000,000 billion cells/mL
(e) 0 - 75% v/v cells spin-down
Accuracy: Range (typical)
(a) 1.0% (as Standard Deviation)
(b) 1.0% (as Standard Deviation)
(c) 1.0% (as Standard Deviation)
(d) 2.5% (as Standard Deviation)
(e) 2.5% (as Standard Deviation)
Linearity: Deviation from a straight line
Range (typical)
(a) 0.02 million
(b) 0.02 million
(c) 0.002 (000,000,000) billion
(d) 0.005 - .05 (000,000,000) billion
(e) 1.5%
Resolution: 1 part in 2000
4-20mA: 0 to nominal full-scale
Enclosure: Indicator electronics NEMA 4X (stainless steel)
Indicator temperature 0 to 60C (32 - 140F)
Sensor assembly pressure to 10 bar (150 psi)
Sensor assembly temperature 0 - 115 C (32 - 240F)
Relative humidity to 100%
Temperature Minimum: 0C (32F)
Window Fouling: Automatic detector (accessory)
Dead Cell Interference: Adjust out per hemocytometer calibration, typically a near-constant value
Trub Interference: Automatic compensation
Yeast Strain Correction: Automatic
Yeast Temperature: Automatic compensation
System Calibration: Transfer from Coulter cell counter, spin-down, hemocytometer, or reference filter insertion
Signal Wavelength: Custom nm
Reference Wavelength: NIR nm
Extension Cable: Up to 120 meters (395 feet)
Outputs 0 to 10, 0.1 V; 1mA; 4-20 mA
Power Loss Effects: Automatic restart
Specification may be changed or improved as necessary.

383-2 East 29th Street | Buena Vista, VA | USA 24416-1293

540.261.1045 voice | 540.261.1268 fax |

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