Varian 979 Series, Operation Manual

Page: 122 / 140

Model 979 Series Helium Mass Spectrometer Leak Detector
B-10
DRAFT 9/15/03
EXTERNAL Uses an external Calibrated Leak (in the test port). For Autocalibrate operations.
FPEAK Adjusts the variable focus voltage to cause a maximum response to helium.
IDLE Turns off the turbo and spectube and waits for a RUN command.
INCREMENT Adds 1 to the Manual Ranging leak rate exponent (making it less negative).
Success is indicated by the normal ok response. Does nothing in auto-ranging
mode. Does nothing upon reaching the least sensitive range.
INTERNAL Uses an internal Calibrated Leak. For calibrate operations.
KEEP Causes the leak detector to close most valves and enter the HOLD state.
MANUAL Sets to manual ranging mode. Success is indicated by the normal ok response.
NOSNIFF Disables the internal sniffer mode.
ROUGH Causes the leak detector to begin a roughing and testing sequence.
RUN Starts the turbo and spectube after IDLE command.
SNIFF Enables the internal sniffer mode.
SYTCATM Sets the current system thermocouple reading to represent atmospheric
pressure. Success is indicated by the normal ok response.
SYTCZERO Sets the current system thermocouple reading to represent a pressure that is
too low for a thermocouple to read. Success is indicated by the normal ok
response.
TPTCATM Sets the current test port thermocouple reading to represent atmospheric
pressure. Success is indicated by the normal ok response.
TPTCZERO Sets the current test port thermocouple reading to represent a pressure which is
too low for a thermocouple to read. Success is indicated by the normal ok
response.
TUNE Adjusts the ion source voltage to cause a maximum response to helium.
VENT Causes the leak detector to vent the test port to the atmosphere.
ZERO Sets the current leak rate measurement to be 0.0 atm cc/sec in the most
sensitive range.
Table B-4 Leak Detection Actions (Continued)
Command Action