SRS Labs QMS 100 Series, Руководство пользователя

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3-20 Programming the RGA ECU
SRS QMS Gas Analyzer
MG: CDEM gain at the HV setting stored in MV. See MG command.
See the Parameter Storage commands list in the next section for details.
Important:
•
The Parameter Storage commands are used by the RGA Windows software to store and
retrieve the partial and total pressure sensitivity factors, and the gain and voltage settings of
the CDEM calculated and used by the program.
•
The parameter values are not used internally by the RGA to correct for sensitivity or gain,
they are simply stored so they can be read and used by any computer connected to the
RGA ECU.
•
MV and MG are only available in units with the CDEM option (Opt01) installed (See MO
command for details) and usually store a calibrated pair of [gain, high voltage] values for the
CDEM.
Programming example
The following list shows a typical application of the storage commands to save ECU specific information
in the RGA ECU. The first line stores a partial pressure sensitivity factor of 0.1mA/Torr, the second line
stores into memory a total pressure sensitivity of 0.02mA/Torr, and the last two lines store a [1400V |
10,000 gain] calibrated pair for the CDEM.
SP0.1 Partial pressure Sensitivity= 0.1 mA/Torr.
ST.02 Total pressure Sensitivity = 0.02 mA/Torr.
MV1400 CDEM HV setting (for MG gain): 1400 V.
MG10 CDEM gain (@MV setting)=10,000x.
Programming the Quadrupole Mass Filter
Use the ML (Mass Lock) command to activate the quadrupole mass filter (QMF) and center its pass-
band at any mass number within the available range. The command ML is included for the convenience
of users who wish to use the RGA as a mass filter. The QMF is parked at the mass requested but no
actual measurements take place. The command’s parameter can be a real number and the step
resolution is 1/256 amu.
The command execution involves two steps:
1. The RF/DC levels corresponding to the mass requested are calculated and set on the QMF
rods based on the mass axis calibration parameter values specified by the last Peak Tuning
procedure.
2. A firmware driven algorithm is then automatically enabled to stabilize the voltage output of
the RF Driver’s controller against temperature fluctuations.