Operation Manual HORIBA APDA-371
Particulate Monitor
Date:
April, 2010
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HORIBA Europe GmbH, Julius-Kronenberg-Str. 9, D-42799 Leichlingen,
: +49(0)2175-8978-0,
: +49(0)2175-8978-50
Page 6
temperature. These values are usually the EPA mandated 760 mmHg and 298 degrees Kelvin (25 °C). Note: Some
other countries use different values for standard temperature and pressure.
Equation 7
Equation 7 can be used to calculate the ambient concentration (C
amb
) from the standard concentration (C
std
) data using
the ambient temperature and pressure. It is necessary to have access to valid data for the ambient temperature and
pressure for the desired sample hour in order to be able to make the calculations.
Example: You have a data value of 27µg from a APDA which was configured to report data in EPA Standard conditions
(298 K and 760 mmHg), but you need to know what the concentration would have been in actual conditions. The actual
average temperature for the hour in question was 303 K and the average pressure was 720 mmHg.
C
amb
= C
std
* (P
amb
/ P
std
) * (T
std
/ T
amb
)
C
amb
= C
std
* (P
amb
/ P
std
) * (T
std
/ T
amb
)
C
amb
= 27 * (720/760) * (298/303)
C
amb
= 27 * 0.9474 * 0.9835
C
amb
= 25.1
µµµµ
g