Stanford Research Systems RGA100, Operating Manual And Programming Reference

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Rear Panel 4-7
SRS Residual Gas Analyzer
ElecMult : The ElecMult LED is turned on whenever the electron multiplier detector is
active (i.e. when a finite biasing voltage is applied across the electron multiplier).
Several different mechanisms can turn off the electron multiplier and its LED: a null bias
voltage request by the user, a Degas process, and an overpressure that shuts down the
filament emission.
RS232 : The RS232 LED reflects the activity on the RS232 Transmit and Receive lines.
ERROR (Red) LED’’s
Error : The Error LED indicates the presence of errors in the operation of the RGA.
Errors can originate from many different sources including hardware, communications,
probe (i.e. bad filament) and operating environment (i.e. overpressure). Troubleshooting
is simplified by an assortment of diagnostic commands built into the firmware, and fully
supported by the RGA Windows program.
Leak : The Leak LED is automatically turned on whenever the filament heater is unable
to establish a requested emission current. The most common reason for this problem is a
serious leak in the vacuum system. In the event of an overpressure detection, the filament
emission and the electron multiplier are immediately turned off, and the Error and Leak
LED’’s are turned on to indicate the problem.
Important: The Leak LED will also be turned on if the Thoria coating of the filament is
excessively worn down or damaged. However, this is a more rare event due to the long
life of the thoriated iridium filaments.
Burnt : The Burnt LED is turned on whenever the ECU fails to detect a filament. A burnt
or missing filament are possible sources for this problem. The Error LED is also turned
on to clearly signal the presence of a filament error.