TSI Instruments DustTrak 8540, Руководство по эксплуатации и обслуживанию

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Chapter 4 28
Four variables can be set for each user calibration.
Name User can input a custom description for the
custom User Calibration.
Photometric
Calibration
Factor Changes the factory calibration of particle
signal, based on Arizona Road Dust, to actual
aerosol being measured.
Size Calibration
Factor Changes the factory calibration of the
particle distribution, based on Arizona Road
Dust, to actual aerosol being measured. This
is for the DRX only. A setting of 1 works for
most situations.
User Cal [on,off] Selecting On will activate current user
calibration and deactivate the previously
selected user calibration.
Determining a new Photometric Calibration Factor
In most situations, the DustTrak
™
monitor with its built-in data logging
capability can provide very good information on how the
concentration of an aerosol changes for different processes over
time. Factory calibration to the respirable fraction of standard
ISO 12103-1, A1 test dust is fairly representative of a wide variety of
workplace aerosols. Because optical mass measurements are
dependent upon particle size and material properties, there may be
times in which a custom calibration would improve your accuracy for a
specific aerosol.
Determining an aerosol-specific photometric calibration requires that
you determine a true mass concentration (e.g., gravimetric analysis)
for the aerosol you want to measure. The true mass concentration is
used to calculate the custom calibration factor for that aerosol. Once
you have a custom calibration factor, you can reuse it each time you
make measurements in the same aerosol environment.
Determining the Calibration Factor for a Specific Aerosol
The DustTrak
™
monitor is factory calibrated to the respirable fraction
of standard ISO 12103-1, A1 test dust. The DustTrak
™
monitor can
be easily calibrated to any arbitrary aerosol by adjusting the custom
calibration factor. The DustTrak
™ monitor’s custom calibration factor
is assigned the value of 1.00 for the factory calibration to standard
ISO test dust. This procedure describes how to determine the