1.1 Principles of Operation
The LFR-6 Sampler is empirically designed to be a more compact version of EPA specifications for PM10
and PM2.5 air sampling at 6 LPM. The LFR-6 Sampler is a microprocessor-controlled portable air
sampler, which can be operated manually or programmed to collect scheduled samples. As specified by
the EPA, all critical air sampling parameters are continuously monitored and logged as time indexed 5-
min averages to validate the sample. These parameters include: flow rate, temperature, barometric
pressure, and accumulated volume. Other sampler related performance parameters are also logged. If
the LFR-6 Sampler is equipped with the Real-Time Particulate (RTP) Profiler and meteorological sensors,
then PM10, PM2.5, wind speed, and wind direction are also included in the data record.
The LFR-6 Sampler can be easily deployed. It can be mounted on a variety of structures using our
universal mounting bracket that can be screwed, clamped, or attached to utility poles, trees, fence
posts, etc. Another option is to use a freestanding tripod.
The LFR-6 Sampler is equipped to operate from either AC or DC power sources. In the DC mode, the
sampler operates from an internal battery pack. A charged battery pack is capable of operating the
sampler for about 30-40 hours. This robust capacity allows the sampler to be used in cold weather and
high altitude applications. A charger is supplied so the batteries can be re-charged in approximately one
hour.
1.2 Particulate Matter Sampling
The LFR-6 Sampler can be set up for TSP, PM10, or PM2.5 particulate sampling by configuring the
sampling inlet components prior to the filter medium. To measure TSP, the omnidirectional Louvered
Inlet is all that is required. For PM10 sampling, an FRM style inertial separator (PM10 Impactor) is
added. To collect PM2.5, the sharp-cut ARA VIS-A Cyclone is attached, which physically selects particles
2.5 microns and below. Common LFR-6 inlet configurations are shown in FIG. 1.
The LFR-6 inertial separators (PM10 Impactor) are designed to operate at a nominal sampling rate of 6
LPM. The LFR-6 Sampler incorporates a microprocessor-based active flow control to maintain the
sampling rate as ambient conditions and filter loading changes. The sampling rate is monitored and
adjusted several times a second and logged at 5-min intervals along with all other important sampling
parameters.
To allow for unattended operation, the LFR-6 Sampler is easily programmed to initiate and stop
sampling. For each sampling event, the LFR-6 Sampler generates a summary of important sampling
parameters such as start and stop times, total sampling volume, and average ambient temperature and
pressure as well as 5-min averages of all ambient and sampler operational parameters. The logged data
file can be easily downloaded to a USB flash drive by the operator. The “csv” (comma separated value )
file can easily be imported into a spreadsheet.
