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Downloading Data MicroVol-1100 User manual 1.6
5.3 Calculations
The MicroVol-1100 flow-controller regulates the volumetric flow-rate of air when the
pump is operating. In-built temperature and barometric pressure sensors collect
ambient data, which are stored in the internal data logger. The MicroVol-1100 uses
the temperature and pressure data to determine the density of the gas.
All current data can be viewed in the Status menu. Historical data can be downloaded
to a laptop computer via the serial port.
Note: Once the internal data logger memory is full, the MicroVol stops
collecting data. If the sample pump is still operating when the memory is
full, then use the current data in the Status menu to read the uncorrected
sample volume in litres (Tot. Vol. l) or the Corrected sample volume in
standard litres (Cor.Volume l).
Using the ambient and Reference temperature and pressure information, the sample
volume is automatically corrected to Standard Temperature and Pressure (STP)
conditions. The MicroVol’s internal data logger stores both uncorrected and STP
corrected sample volume data in the internal memory. The sample volume data is
used to calculate the mass concentration. The mass concentration may either be
reported at STP corrected conditions, or at actual ambient conditions by using the
relevant sample volume data in the calculation. Refer to local reporting standards.
The STP Reference conditions have been factory set, but may be changed via the
Setup menu:
Mass concentration data is generally reported in
μ
g/m
3
referenced to standard
temperature and pressure (STP). There are, however, different accepted values of
STP:
Standard Temperature Standard Barometric Pressure
mmHg
°
C (K)
MicroVol Setup
menu parameter
Ref. Temp Ref. BP
Australia,
Europe
0
°
C (273.18K) 760
USA 25
°
C (298.18K) 760
Japan 20
°
C (273.18K) 760
Note: 760mmHg = 760Torr =
101.325kPa = 1 standard atmosphere
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