Varian 990 dCLD II, Operation Manual

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Model 990 dCLD II Component Leak Detector
3-7
3.3 Initial System Parameter Setup
The 990 dCLD II performs functions and tests based upon parameter values. Some parame-
ters are entered and set when the system is assembled and tested. Some parameters are cal-
culated and change automatically during power up, Calibrate, or Zero functions. Other
parameters should be changed when a change is made to the physical system, such as when
the button thermocouple (TC), ion source or preamplifier is changed. What these parame-
ters are set to are a function of the physical configuration and sensitivity needs as was dis-
cussed in the previous section and in more detail in Section 2.
Adding to the stability and reliability of the 990 dCLD II, several parameters relating to the
operation and performance are stored in EPROM in the control unit. This means if you lose
power, or when the control unit is shut off, you do not lose that information. Parameters can
be viewed and changed through commands entered via the rear serial port or the optional
front control panel, if it is installed (refer to Section 4, “Setup and Monitor Operations
via the Optional Front Control Panel”).
This section explains each of the parameters and what happens during the related function;
related functions or parameters are grouped together. There is also reference to the area in
the document where you can find information on how to set the parameter or perform the
function. Remember, Table 2-11 on page 2-15 cross references functions and how to set
parameters across all operating modes.
3.3.1 Parameters and Operating Modes
The parameters and operating modes work together to perform leak detection, and what
you enter determines the type of test and sensitivity of testing performed. The discussion
below includes an explanation of what the parameter or function means, so you know how
to use it for your system and how to set it in varying operating modes. Some parameters are
grouped together so you can see how they relate to one another or affect an operation.
NOTE
For more information on how to set a parameter or select a
function, refer to the following:
❑
Appendix A “Communications Protocol”
❑
Appendix B “Customer Accessible Inputs and Outputs”
❑
Section 4, “Setup and Monitor Operations via the
Optional Front Control Panel”
❑
Table 2-11 on page 2-15, Cross Reference of Commands
for Operating Modes