TSI Instruments SIZER 3321, User Manual

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4-4 Model 3321 Aerodynamic Particle Sizer

Spectrometer
Command
Function ( see also Appendix C for serial commands
related to Menu Items ).
Laser Power [%] Displays the percent of laser power used from 0 to
100%. Default is 75%. This value is field selectable but
should not be changed except for diagnostic purposes.
Changing this setting will alter the calibration. Refer to
Chapter 5 or Appendix C .
Laser Turn the laser on and off. Default is on. Generally, the
laser is on whenever the instrument is running. You
might want to turn it off for diagnostic purposes.
APD Voltage [V] Displays the voltage of the Avalanche Photodetector
(APD). Changing the APD voltage with this setting
disables APD autocalibration (see below).
APD Max Vop [V] When the APS
™ spectrometer is powered up, the APD
voltage is set to APD Max Vop based on the temperature
of the APD. This temperature compensated setting
should give the APS
™ spectrometer the maximum
sensitivity to small particles.
APD
Autocalibration Enables the APD temperature compensation algorithm
when set to On. When set to Off, the APD voltage will not
change with APD temperature. This setting will always be
enabled when the instrument is first powered on.
Alarm Level
[pt/cm
3
]
Level of total particle concentration at which the APS
™
spectrometer will issue a high concentration alarm. The
HI CONC led on the front panel will be turned on and the
high concentration flag (see RF command) will be set;
and if the sound is turned on, the APS
™ spectrometer
will beep. Default is 1000.
End of Sample
Pause When enabled, this setting freezes the display for 4
seconds at the end of a sample when in continuous
sample mode. This gives you a chance to view the
sample or to select Pause from the main menu. Default
is off.
Display Image Set the image Positive/Negative for the LCD display.
Positive is black letters on light background. Negative is
white letters on dark background.
Firmware Version Displays the version number of the firmware installed in
the APS
™ spectrometer.
Exit Exit the Menu and display graphical information.
C o l l e c t i n g D a t a
After the Model 3321 APS
™
spectrometer is set up and operating as
desired, use the computer and Aerosol Instrument Manager software to
collect, save, interpret, and print sample data. Refer to the
Aerosol
Instrument Manager
®
Software for APS
™
Sensors Manual (P/N 1930064)
for more information on operating the software.