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Every 30-minutes the 1 hour and 3 hour average concentration is
calculated as a mean value from the latest two (2) and six (6) 30-minute
average concentration values, respectively.
After midnight (00:00), the daily average concentration is calculated from
the valid 30-minute averages of the previous day.
The 30-minute average, 1 hour average, 3 hour average, and 24 hour
average concentrations are displayed on the Model 5030 LCD display by
pressing "DISP". These data are also available via the serial interfaces
(COM1, COM2) by remote commands and print format command.
The Model 5030 airflow schematic is shown in Figure 1-2. This figure
shows the general locations of the ambient, sample, and heater wall
temperature sensors; the upstream sample RH sensor, the vacuum,
differential orifice, and barometric pressure sensors; and the vacuum pump
controlled by variable speed.
Through proper sensor placement a continuous air density correction is
applied to the beta attenuation derived concentration. A dynamic average
of this concentration is continuously calculated. The ratio of the dynamic
beta concentration to the dynamic nephelometer concentration is also
continuously calculated. This ratio is then used as a correction factor (CF)
for the one-minute average nephelometer reading. Therefore, the following
applies:
SHARP
where:
N
n
= Nephelometer 1 minute running average (μg/m
f_1
τv = Dynamically filtered Beta-derived concentration (μg/m
C14
f_
Nf_τv = Dynamically filtered Neph-derived concentration (μg/m3).
τv / N
= N
n * (C14
n
f_1
f_
Model 5030 SHARP Monitor Instruction Manual
Introduction
Calculation of Concentration Averages
τv)
f_
n
3
).
3
).
1-7
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