Varian 979 Series, Operation Manual

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Model 979 Series Helium Mass Spectrometer Leak Detector
1-18
DRAFT 9/15/03
1.10 Specifications
The specifications for the 979 Series Leak Detector are provided in Table 1-1.
Table 1-1 979 Series Specifications
Specifications 979 Helium Mass Spectrometer Versions
System Sensitivity Standard Sensitivity High Sensitivity
High Vacuum Pump Type,
Air-cooled,
maintenance-free
Vacuum Technologies Turbomolecular Pump
Rough/Fore Pump Wet (Oil-sealed) Dry (TriScroll

) Wet (Oil-sealed) Dry (TriScroll

)
Rough Pump Type
Free Air Displacement
l/min, 60/50 Hz
— SD-451 — TS-620 — SD-451 — TS-620
— 410/342 — 500/420 — 410/342 — 500/420
Fore Pump Type
Free Air Displacement,
l/min, 60/50 Hz
DS-302 DS-302 TS-620 TS-320 DS-302 DS-302 TS-620 TS-320
285/237 285/237 500/420 250/210 285/237 285/237 520/420 250/210
Minimum Detectable Leak,
atm-cc/sec
5 x 10
–10
5 x 10
–11
Leak Units atm-cc/sec, mbar-l/sec, torr-l/sec, Pa-m
3
/sec
Response Time Less than 0.5 second, in accordance with AVS Standard 2.1.
Amplifier Drift Less than 5% of full scale of the most sensitive range, in accordance with AVS
Standard 2.1.
Noise Level Less than 5% of full scale, peak-to-peak, in accordance with AVS Standard 2.1.
Calibration Fully automated tuning and calibration using the internal or external calibrated
leak. The fast calibrate feature allows the standard version to calibrate in less
than 20 seconds and the high sensitivity version to calibrate in less than
1 minute.
Zero Control Selectable mode background elimination with unique AUTOZERO<0 feature.
Leak Indication A 50-segment bar graph (linear or log) indicator displays leak rates
automatically; alphanumeric indication on LCD display. A leak can also trigger
an audible alarm frequency that varies in proportion to the size of the leak,
dedicated volume control and programmable audio threshold. Analog voltage is
proportional to the leak rate.