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The requirement for filter efficiency
measurement (contamination control) has
been outlined for years by ASHRAE 52.1 as a classical gravimetric method. Since the
concentration of smaller particulate in ambient air is dramatically increasing, new
methods need to be developed for air cleaning devices to study the removal efficiency by
particle size. The new ASHREA standard 52.2 soon will be in effect.
GRIMM’s
new Portable Fine Dust Particle Size Distribution Analyzer, Version 7.309, is designed to
fulfill US ASHREA 52.2 five-category/twenty subgroups. It is also useful for the European
nine-category Method Eurovent 4/9 for testing coarse material and/or
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General Ventilation Filters, Germany DIN 24185
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Air filters of fractional efficiency and the Euro-standard EN 779
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Respiratory Protective devices, Europe, EN 143
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Half Mask Testing requirements, Europe, EN 149
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Engine and Compressor Filters, Europe, EN 1822
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Many more standards for specific applications.
Key Features
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Measurement Range: 0.01 to 100,000µg/m3, or 1-2,000,000 Particles/liter,
without range change.
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Useful for most dust masses or dust types (even DOP, DEHS, etc...).
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Constant precision over entire measurement range.
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Automatic control of the laser- and airflow.
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Digital output as RS 232 of all attached sensors and the two
spectrometers.
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Data Storage on removable memory cards
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LED status display for counts/or mass, sensors, data, time, etc...
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Display of error functions, battery power, etc.
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Complete remote control via laptop/PC.
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Portable, battery driven, complete unit weighing only 6 lbs. (2.8 kg)
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Stainless steel Isokinetic sampling , with automatic flow control system
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Real-time particle size distribution in 12 ranges from 0.25 to 3 microns
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Built-in pressure differential sensor to be connected to the filter
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Attachable wind speed sensor, so variable air flow can be recorded
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Temperature and humidity sensor for aerosol study attached
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Measured dust is sampled on removable PTFE filter for analysis
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Comes in solid carrying case, easy installation in the field,
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Can be connected to a laptop to read results in real time.
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Possible wind velocity changes and associated mass distribution changes
can be displayed
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Filter Efficiency change in relation to particle sizes can be displayed
(Most Penetrating size).
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Pressure change in relation to the dust load and particle size can be
demonstrated.
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Recovery time of filters after clean up can be determined.
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The influence to temperature and humidity changes of aerosols can be
demonstrated.
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Gravimetric or chemical analysis after measurement of removable filter
possible.
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Easy installation of the system in existing ventilation/ wind tunnels,
since only two one-inch openings needed.
Sampling Method
One isokinetic sampler, measuring from
2-20m/sec. is inserted before and one behind the test filter in the wind tunnel.
In addition temperature, humidity, wind speed and pressure sensor pipes
are entered in the same tunnel. All sensors are connected to two parallel Model 7.309
instruments. The complete system can be battery operated for four hours or with 110/220
VAC 50/60HZ. All data may be stored by using a removable data logger card and/or directly
transferred via RS-232 to the attached laptop.
The
GRIMM 7.309 operates on
an optical principle. A laser diode sends a light beam directly into the sample air.
Each signal from each particle scattering light is collected, classified by size and then
counted. The results are expressed ten times per minute in counts or mass
distribution by size channels. A volume controlled pump samples air constantly and all
measured particles are collected on a removable filter (for later chemical analysis).
The above picture shows a schematic of the
complete system consisting of the two lsokinetic samplers connected to the (1) two
spectrometers, the (4) pressure sensors and (5) temperature/humidity/wind
speed sensors. All are connected and controlled by the laptop, even the
aerosol generator (3,optional).
The gravimetric dust mass by weight determination (common for most classical standards)
can also be performed with this optical spectrometer. All isokinetically
collected and measured dust is sampled in two separate PTFE filters, one upstream
and one downstream of the test filter.
Filter Data
Acquisition and Presentation
All data for the two
aerosol spectrometers and (optional) sensors are stored on the two data logger cards. These
results can be transferred to the PC and are displayed in different numerical and
graphical modes such as:
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Dust concentration (UP/DOWN in µg/m3)
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Particle count distribution (UP/DOWN in 12 size ranges)
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Wind velocity (in m/sec.)
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Pressure (in Pas)
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Temperature and humidity (Co + %)
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Collected dust on removable filter (µg/volume)
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Efficiency by particle size in %
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Penetration by particle size in %
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Real time Efficiency/Penetration by different sizes
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Instant curve of Filter recovery
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Instrument diagnostic/service page
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Filter class performance (optional)
Each Measurement is based on the UP and DOWN stream data
tiles. Results are shown as counts (or mass) and expressed as percentage of efficiency
over size and kind of aerosol. Above are the current physical parameters of the four
sensors shown in the graphical mode. This data is stored and updated automatically 10
times per minute.
Below are Efficiency Curves in percentages of 12 different particle size channels
expressed in real time. This kind of graphic displays the filter recovery time in relation
to size.
The 3-dimensional Mean Penetration Curve of an air filter, exposed to DOP oil mist over
10 min., is shown above on the right. In addition, we offer five more ways of
graphical data presentation.
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Technical Specifications
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Measurement range: 0.01 to 100000 µg/m or 1 to 2000000 particle/ litres,
without range change
• Useful for most dust masses or dust-types (even DOP, DEHS, etc...)
• Constant precision over entire measurement range
• Automatic control of the laser- and airflow
• Digital output as RS 232 of all attached sensors and the two
spectrometers
• Data storage on removable memory cards
• LED-status display for counts/or mass, sensors, data, time...
• Display of error functions, battery power, etc...
• Complete remote control via laptop/PC.
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Measuring from 1 to 2,000,000 particles/Iiter
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1.2 I/min. air sampling pump with air volume control system
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Filter holder for 47mm Teflon filter
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Automatic self-diagnostic system
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Possible digital data display on 2 x 16 digits displaying every 6
seconds:
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2 of the different size channels such as distribution above
0.27/0.3/O.35/O.4/0.45/0.5/0.6 as well as 0.7/0.8/0.9/1.0/1.6 micron
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Total sampled air
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Gravimetric correction (C-factor) value
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STAND BY mode
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Alarm value and battery power
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Time and date
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Sampling location
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Monitor serial number and hours in use
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Built-in RS 232 interface connection for printer or computer.
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Built-in slot for one 512 (or larger) data storage card
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Space for lead storage battery, (6-7 h of operation)
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Connection for signal inputs from temp./rel. humidity/air velocity and
pressure differential sensors
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For 220V/5OHz or 11OV/6OHz and battery operation.
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Weight 1.7kg (3 lbs) net, size 24x 2x6cm (9.5
x4.5x2.5").
Sampling and Sensor System
2 lsokinetic samplers in stainless steel for wind
speeds from 2.0 to 20.0 m/sec.
1 Climatic Sensor for wind speed, relative humidity and temperature
1 Pressure differential sensor
Electrical Specifications
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Power supply: |
230 VACS/] 10 VACS, 50/60 Hz’s |
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Consumption: |
0.7 VA with Laptop |
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Signal outputs: |
2x RS-232 |
Carrying Case Specifications 7.300
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Housing: |
Material in Polyurethane / RIM) with inserts for all accessories |
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Temperature: |
Range from +5 to +55oC (35-120oF) |
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Dimensions: |
430 x 420 x 290 cm (17" x16.5" x11.5") |
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Weight: |
15kg (32 lbs) including laptop |
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