300781172_002_C0 - 012/2019 - © Leybold 64
Maintenance
11.3.4 Confirm the sensitivity (Faraday Cup)
1. Procedure: Set a Gas flow into the sensor of between 1 x 10
-4
Pa and 1 x 10
-3
Pa (LEYSPEC view and LEYSPEC ultra models).
We recommend Nitrogen or Argon gas.
Example: Introduce Nitrogen gas up to 5 x 10
-3
Pa
2. Recipe settings:
Mode: Trend
Ionization Voltage (WR only): 70 eV.
Unit of Y axis: [A] (Current)
Measurement mass number: Flowing gas (such as N
2
gas m/z = 28)
3. Control settings
From the Sensor menu, open Control Panel and make these settings:
Ion collector = FC
Emission current =
500
μA LEYSPEC view models (fixed value)
500
μA LEYSPEC ultra models
Purpose: Sensitivity of the ion source reduces during continuous operation. When the
sensitivity is reduced, it becomes difficult to detect small fluctuations in partial
pressure.
Cycle: The rate of reduction depends on the operating conditions (gas species,
pressure). We recommend that you confirm the sensitivity and its reduction
about once a month.