Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS)
DOC-0210 Rev E-4
5 5
© 2017 DROPLET MEASUREMENT TECHNOLOGIES
Appendix A: Output File Data Channels
The UHSAS data file is an .xls file. For each sampling period, the file records the channels listed
below. Sampling periods are listed in rows, while data channels are listed in columns.
Date
: The current date in mm/dd/yyyy format.
Time:
The time at which the current sample began.
Accum.
(sec)
: The current sample time setting, i.e. the number of seconds during which the
sample accumulates counts.
Scatter (Volts)
: The background DC molecular scatter level from the APD. This channel is used
during troubleshooting with DMT technicians.
Current (Volts):
The current being supplied to the instrument.
Sample
(
sccm):
The flow of the sample air, which should be between 1 and 100 sccm. The
instrument is factory calibrated at 50 sccm, so this is a good sample flow setting.
Ref. (Volts):
The laser reference voltage from the monitor photodiode. Ideally, this voltage
should be between 1.75 and 2.75. If the reference voltage drops by 25% or more, the laser
optics may need to be cleaned.
Temp (Volts):
The voltage from the temperature sensor.
Sheath (sccm):
The flow of the sheath air, which is typically 700 sccm.
Diff. (Volts):
Not used.
Box (K):
The temperature of the electronic box, i.e. the temperature just as the sample enters
the instrument.
Purge (sccm):
The flow of the purge air. The purge flow is used to keep the laser optics clean.
Pres. (kPa):
The ambient pressure.
Aux. (Volts):
Not used.
Flow (sccm):
Not used.
After these channels, the file lists the particle counts for each bin. The bin boundaries appear in
the header of each column.
