FH62I-N Beta Attenuation Monitor
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Andersen Instruments Beta Gauge is the most advanced system for automatic, continuous, and accurate ambient articulate sampling. Model FH621-N is the only beta gauge that utilizes a truly continuous 60 minute to 24 hour sampling cycle, eliminating a step-wise response to move the filter. The system is also insensitive to vibration and does not require frequent
visits to change the filter. The Krypton 85 radiation source is contained in a stainless steel capsule, where the Beta energy makes it possible to measure even large mass values of particles on the filter. The system can stand alone in an outdoor shelter or used indoors due to its sensitivity to changes of ambient temperature, pressure conditions, and humidity. This accuracy is achieved by a unique dual beam two detector principle. Andersen's Beta Gauge does not require a user's radiation license.
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The Andersen FH621-N Beta Gauge Sampler is designed to continuously measure
the mass concentration of PM 10 particles in ambient air. The beta gauge
sampler is EPA approved for continuous PM 10 compliance monitoring and is
also used extensively for Pollutant Standard Index (PSI) networks. The
FH621-N is the only beta gauge sampler that can be directly calibrated in
the field with a set of calibration control foils and the only beta gauge
sampler that collects and measures at a single filter-spot position. The
sampler also does not heat the measurement chamber which, if heated, can
drive oft volatile particles and cause errors in measurements. A complete
FH621-N Beta Gauge consists of three main components: the central
instrument, pump, and SA246B PM 10 inlet. The central instrument includes
filter strip mechanism, radiation measuring chambers, LCD display with
control keys, and the complete electronic circuitry.
Features
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Low maintenance and low operating costs
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Approved EPA Equivalent Method Designation (EQPM-0990-076)
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Accurate PM 10 measurement for both EPA 24-hour averages and hourly episode
studies
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Low detection limit and high accuracy
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Determination of mass concentration is independent of particle shape, color and
size available as TSP, PM 10, or PM 2.5
SA246B PM-10 Inlet
Suspended particles in ambient air enter the 10 micron inlet at a flow rate
of 16.7 LPM (1CMH). The parallel plate inlet, insect screen, and conical
flow deflector yield accurate sampling independent of wind speed and
precipitation. Air is drawn into the inlet and deflected downwards into the
acceleration jet of the impactor unit. By virtue of their greater momentum,
particles larger than the 10 micron cut-point impact out and are retained
in the middle plenum impaction chamber. The particle fraction smaller than
10 microns is carried vertically upward by the air flow and down the vent
tubes to the beta gauge sampler. (PM2.5 and TSP inlets am also available).
Principle of Beta Attenuation
Ambient air is pulled through the PM 10 sample inlet and dust particles are
deposited on the glass fiber filter tape. A low level of beta radiation is
emitted from the source which passes through the filter tape and deposited
dust. The increase of particles collected on the tape causes a lower
beta-ray measurement in the measuring chamber. Them is direct mass
collection and simultaneous measurement at this single filter-spot position
which results in continuous observation of the Increasing dust mass and
corresponding concentration. A compensation chamber receives an equal
portion of the beta-ray and is used as a reference by comparing the sample
measurement In the measuring chamber with transmitted energy through a
compensation chamber foil which exhibits the same absorptivity as a clean
filter tape. As particulate matter is collected on the filter, the
differential reading changes and the signal is converted by an on-board
computer to PM 10 concentrations. Ionization chamber are used as radiation
detectors because of their excellent temperature stability and practical
unlimited life time. Output from the instrument can be through visual
display1 on board computer, telemetry, printout, or storage in an auxiliary
disc.
Specifications
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Measuring Principle
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Direct mass collection and simultaneous
measurement by a dual beam compensation
method and single filter-spot position.
(No step-wise response with preselected
time and range intervals)
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Type of Basic Output Function
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Integral function mass over time
(continuously observed)
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Measuring Range
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5 to 10,000 ?g/m
3
; peaks up to 20,000
?g/m
3
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Minimum Detectable Limit
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Less than 2 ?g/m
3
(24 hr)
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Accuracy
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2 ?g/m
3
(24 hr)
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Measurement Cycles
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Continuous observation of the increasing
dust mass during sampling (not
step-wise). The time of full load of
filter in which one single filter spot
remains in the same position is: Ambient
concentration of 50mg/m
3
: 24 hr at (1
?g/m
3
) flowrate
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Output Signals
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0-10 V for concentration and mass over
time
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Optional Output Signals
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0-20 mA: 2-20 mA; 4-20 mA (life zero)
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PrinteriComputer Interface
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V24/RS232 C serial interface
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Scanning Time
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5 sec. 4 mm. (automatically)
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Air Flow Rate
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1 m
3
/h
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Flow Rate Regulation
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Intemal (PI-type)
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Stability of Flow Rate
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+/- 0.3% with regulator
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Operating Temperature
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-10?C to +50?C
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Pump Type
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Rotary vane pump with carbon vanes
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Time Between Calibration Checks and Maintenance
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4 months (automatic zero during running)
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Type of Calibration Checks
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Set with 2 mica foils (zero and
span/mass)
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Filtering System
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Glass fiber filter tape (width: 40mm;
length: 30m)
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Consumable Materials Per Year
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1 set of carbon vanes for pump 1; 2
filter tapes
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Sampling Heads (Inlets)
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-TSP (1 m
3
/h) total suspended particulate
-PM 10(1 m
3
/h). Inhalable particulate 10
?m
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Microprocessor
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Controlled PC Connection, Auto
Calculation, Data Storage, Built-in
Diagnostics
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Status Signals
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Filter Break, Air Flow, Zero Adjustment,
Filter Change, 2 Alarms
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r
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Power Supply
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110v/50-60 Hz or 220v/50/60 Hz
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Models
The
FH621-N
PM 10 Beta Attenuation Particulate
Monitor, 110v/60Hz includes:
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FH621
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19" Rack
Mount Beta Monitor
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SA246B
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PM 10 Inlet
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FH102
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Accessory
Kit. Includes:(2) FH111-2 Filter Tape Rolls & Hardware
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FH107
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Roof Flange
Kit. Includes: FH122 - Flat Roof Mounting Flange
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FH120
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72" Drift
Tube to connect Beta Monitor to Roof Flange
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FH118
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22" Inlet
Tube to connect Roof Flange to Inlet
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FH104
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D.O.T. Shipping
Crate
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The FH621-NOP1(Indoor) model also comes with an indoor 19" cabinet
The FH621-NOP2(Outdoor) model also comes with an outdoor weather enclosure
Note: For U.S. EPA Equivalent Method Designation FM125 Calibration Mass Foil Kit is required. One calibration kit can be used on multiple units.
FH125 Calibration Kit - Calibration Mass Foil
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