- Quick
window removal, cleaning and replacement; solves solids build-up and
other "window problems”
- Rugged
design is ultra-sealed to prevent moisture migration.
- Replacement
caps allow line to operate without cells installed.
- "Robust"
equipment
How
it Works
 Consisting
of a flow cell unit, two modular optical cells: one for the NIR-UV
radiation source, the other for the scanner; and an indicator/controller
cabinet, the KSA family of concentration analyzer systems continuously
monitor chemical concentration by direct across-the-pipe measurement of
absorption peaks in the production/quality control environment.
McNab
fixed-filter KSA instruments measure the change in radiation received from
the NIR-UV source to the scanner photocell detecting unit.
These signals are transmitted to an indicator/controller unit that
contains the electronic circuitry necessary to process the signals, to
display the readings, to input desired set points, to indicate alarm
levels and to operate alarm relays. It
also has continuous output for proportional control connections.
The
Model KSA uses the very latest optical technologies to provide stable,
low-noise signals across the NIR range.
Collimated NIR-UV radiation is directed through the process fluid
stream to the detector unit that generates electrical signals. These
signals are preamplified and sent to the indicator/controller cabinet,
which compares the NIR-UV signatures with those for which the KSA has been
calibrated. The ratio of the
NIR-UV signature and the background process fluid signal is calculated,
allowing the instrument to instantly self-correct for changes in the fluid
stream caused by such items as color, turbidity or window fouling.
As
the flow cell unit is pipe-mounted, the KSA provides immediate
across-the-pipe measurements at operational pressures and temperatures.
Distortions caused by sample temperature and/or pressure changes are
avoided, as are other compromises normally required of off-line sample
lines or with laboratory analysis.
The
across-the-pipe optical path can he visually inspected any time during
operation without pipe shutdown, and McNab’s unique modular optical
cells can he quickly hand-removed for off-line inspection, pressure test or
replacement. This design has eliminated the traditional problem of broken
window glass and fogging.
Unambiguous
calibration is accomplished via the built-in calibration slot in the
scanner housing.
From
Ultraviolet to Near-Infrared
Model
KSA spectroscopic analyzers measure chemical concentration in process
liquids with:
-
Automatic
calculation for direct concentration readings
-
Self-correcting
optics and electronics
-
Time
proven design; thousands of modular optical cells installed since 1960
-
Selectable
path lengths
-
In-pipe
span calibration using reference filters without flow interruption
Model
KSA instruments utilize a unique calibration method that allows simple
verification without flow interruption.
Such in-process verification offers great savings in terms of time
and expenses related to flow interruption, line dewatering and sensor
disconnection; and because the pipe is never opened, hazardous or sterile
conditions are nor compromised.
Calibration
may be accomplished using a standard reference optical filter cartridge,
which offers reliable analyzer testing for its quality assurance
documentation (ISO 9000 and others.)
 In
Figure 1 below, the vertical axis represents the optical density of the
cartridge; the horizontal axis shows the resultant KSA meter reading. The
readings verify the KSA's accurate operations.
Advanced
Optical And Electronic Design Provides Greater Range
The
KSA's electronics have been specially designed so that the digital meter
readings can be adjusted to fit parts-per-million (ppm) units following
the Lambert-Beer Law of optics, as:
M
= A = ELC,
where
M = Meter Reading
A
= Absorption
E
= Extinction coefficient
of
substance
L
= Sample path length within pipe
C
= Concentration (in PPM)
Modular
Optical Cell
 The
KSA flow cell assembly consisting
of the flow cell unit and two head assemblies houses the sensor detector,
electronics and McNab’s exclusive modular optical cells.
The
modular optical cell includes the pressure seal, window, collimating
optics, air purge vent and a unique 4-gasket sealing system that prevents
moisture migration into electrical conduits; protecting against false
readings and preventing equipment damage.
McNab’s
modular optical cells contain all the elements that may he optically
degraded or severely coated by the process, e.g., windows and gaskets. The
optical cells may he removed, cleaned and reinstalled in less than five
minutes, avoiding long down-times and costly delays associated with
spool-piece removal.
A
temporary quick-removal cap allows the process line to operate while the
modular optical cells are removed.
Other
Photometric Instruments
The
KSA is factory-customized to spectroscopically measure specific chemical
concentrations based on their near-infrared or ultraviolet signatures.
Other McNab instrumentation is available to provide photometric analysis
of such items as turbidity – using monitors that measure with
nephelometric (scatter) and forward-scatter technologies for the
measurement of low-level turbidities (NTU, PPM, EBC, etc.) – as well as
color, high-level chemical concentration, optical density and others.
Contact McNab for more information.
McNab, Inc. is located in metropolitan New York City. Our offices in Mount
Vernon, New York include our research & development laboratory, design
engineering department, modern manufacturing plant and automatic testing
facilites to evaluate our products. McNab's Quality Assurance
Process meets Mil-I-45208. We also maintain an engineering and parts
facility in Europe.
Model KSA
|
| Principle of Operation: |
Direct-reading spectroscopic comparison
of intensity of NIR/VIS/UV radiation before and after it has passed
through a liquid.
Attenuation of radiation as a measurement of change of chemical
concentration. |
| Specifications: |
Contact
McNab for specific technical notes. |
| Range and Units: |
200 - 2,500 nM in customer-specified
units. |
| Ambient Conditions: |
-10° - 158°
F (-23° - 70° C),
0-100% relative humidity |
| Recorder Output: |
0-1 mA or 0-0.1, 10 V |
| 4-20 Output: |
Two-wire, ground isolated powered
(channel 1). Two wire, unpowered for computer (channel 2) |
| Alarms: |
Two independent adjustable set-point
alarms with warning of NIR-UV source failure/obscured lenses/power
loss. SP/DT 5A resistive, unpowered contacts. |
| Power Requirements: |
115/230 VAC, 50/60 Hz switch selectable,
75 Watts max. |
| Housing: |
NEMA 4 (Watertight), 4X (stainless),
hinged door 13"W x 16"H x 7 1/2"D; (33 x 41 x 18 cm)
for wall mounting. |
| Weight: |
25 lb./11.3kg. |
Flow Cell Assembly (available separately)
|
| Range: |
Follows indicator. |
| Style: |
Standard or sanitary designs. |
| Optics: |
Four-filter method. |
| Light Path: |
Appropriate to absorption level. |
| Material: |
Stainless steel, ASTM 316L/DIN 4435,
others available. |
| Windows: |
Vitreous silica. Other material as
required. |
| Seals: |
Gaskets to match process. |
| Detector: |
Instantaneous Four-diode typical; photo
conductive as required. |
Flow Chamber
|
| Specifications: |
Unrestricted, full-diameter flow or to
suit application. |
| Operating Pressure: |
150 psig, 10 bar, PN 10. (Contact factory
for higher ratings). |
| Operating Temperature: |
-10° - 225°
F (-23° - 115°
C). For up to 480° F (250° C) contact factory. |
| Enclosures: |
NEMA 6 (submersible), IP68. |
| Separation from Indicator |
250 ft. (75 meters). |
| System Calibration: |
Permanent reference filter. |
| Accessories: |
Extensive users manual, regulated power
supply. |
| Service: |
Commissioning, preventive maintenance, and filter
selection laboratory work-up. |
| Specifications may be changed or
improved as necessary. |
A95-01
|
McNab
accepts all major credit cards.
