INFICON Helium Leak Detector Modul1000 - Manual (Page 8)

1-6
Operating instructions
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1.3 Graphic conventions
Notice: Points to very useful pieces of information.
1 Points to an operation that you have to perform.
⇒ Points to the result of an operation you accomplished.
→ Points to the button you have to press.
• Shows a listing.
1.4 Definition of Terms
Autotune / Mass alignment
The Modul1000 adjusts its tuning voltage to determine the optimal voltage for peak
efficiency.
Autoranging
The range of the pre-amplifier is selected automatically. The Autoranging feature of
the Modul1000 covers the entire range or leak rates depending on the selected oper-
ating mode. Vacuum mode or Sniff mode Not only the leak rate signal, but also the
pressure in the test sample (inlet pressure PE) and the fore-vacuum pressure (PV)
are used for control purposes.
Auto zero
Determination and automatic adaptation of the helium background in the Vacuum
mode. Through this function, the internal zero level of the instrument is determined
which is then subtracted from the current leak rate signal. This function is run during
the calibration process or when operating the start push-button, provided the
Modul1000 has been running previously for at least 20 seconds in the Standby or
Vent mode. If the helium background previously suppressed should drop, the zero
level will be adapted automatically.
Fore pressure
Fore pressure between turbo pump and fore pressure pump.
Internal helium background
The existing helium partial pressure in the measurement system. The level of the
internal helium background is measured in the Stand-by mode and subtracted from
the measured signal. (see above: Auto zero)