INFICON Composer Gas Concentration Controller - Manual (Page 98)

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Composer Operating Manual
4.1.2 Optional LCD Display
The parameter set may be downloaded to the instrument in any of the methods
listed in
section 4.1.1 above or manually using the controller’s keyboard.
Manual entry requires placing the instrument in the Program mode by pressing
the PROG key on the front panel; see
section 4.3.5.3 on page 4-17 . The
Program mode will be identified by the presence of a blinking cursor, adjacent
to the highlighted parameter. There are no cursors in the Operate mode.
Parameter data is entered by pressing the appropriate numerical or Y-N key to
define the parameter followed by the E key which enters the data into memory
and simultaneously highlights the next parameter.
There are nine possible sets of this information that can be stored. These data
sets are called programs and are identified on the display as PROG # (where #
is the data set being modified). Control and target parameters may be modified
while the instrument is operating (controlling), but only on the current parameter
set. The instrument must be in STOP mode to modify any other parameters.
When returning to Operate mode, the last parameter set displayed will be used.
4.2 Calibration
Calibration is an optional procedure for this Instrument System. The purpose of
calibration is to obtain the exact frequency (speed of sound) for the carrier gas
(or one component of a mixture) for the particular instrument’s operating
conditions. This is called Reference Zero. For many applications, the Factory
Zero may be sufficient to provide the needed levels of accuracy and
reproducibility (refer to
section 3.1.3, How is Performance Affected if I Use the
Factory Set Reference Zero Value?, on page 3-2 ).
4.2.1 Frequency of Calibration
Applications requiring the highest degree of reproducibility should have the
Reference Zero reset daily. Experience will determine if less frequent
calibrations are appropriate. Refer to
section 3.1.2 on page 3-1 , section 3.1.3
on page 3-2 , and section 3.1.12 on page 3-10 for additional information on this
topic.
4.2.2 Special Tools and Materials
A means of flowing a pure gas through the Transducer at the processes’
pressure and flow rate is required for setting the Reference Zero.
For guaranteed safe operation, a calibrated high performance mass
spectrometer leak detector should be used whenever the Transducer has been
removed and reinstalled.