Stanford Research Systems RGA100, Operating Manual And Programming Reference

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Detection Control Commands 6-39
SRS Residual Gas Analyzer
Notes :
x
This mass axis correction procedure can also be triggered at any time, by
itself, using the RS and RI commands with no parameters (See Tuning
commands).
x
The correction procedure is also automatically performed at the beginning of
all analog and histogram scans. However, no correction is performed at the
beginning of single mass measurements since the extra checking would
significantly extend the time it would take the measurement to be completed.
x
Please see the Peak Tuning section of the RGA Tuning chapter for more
details on mass axis calibration requirements under small and large
temperature fluctuations in the RGA Head.
x
Remember that the CA command turns off the RF/DC voltages at the
end of execution.
Parameters: Only one possible command format is allowed
CA
Error Checking:
An attempt to pass any parameter with CA results in a bad-parameter error being
reported.
CL
Description : Calibrate Electrometer’’s I-V response.
Echo: STATUS error byte.
Perform a complete calibration of the electrometer’’s I-V response.
The calibration procedure calibrates the output of the electrometer against input
current over its entire operating range, and stores a calibration table in the non-
volatile memory of the RGA Head.
Instead of simply relying on the intrinsic
logarithmic I-V behavior of the electrometer, a digital logarithmic interpolation
algorithm calculates the currents from the calibration curve during
measurements.
The procedure takes several seconds (longer when CDEM option is installed) and
its completion is signaled to the host computer by returning the STATUS byte
value.
Important :
x
The electrometer is designed for maximum long term stability, however, it is
good practice to recalibrate it periodically, particularly in the presence of a
large change in the operating temperature of the RGA Head.