INFICON Guardian EIES Controller - Manual (Page 61)

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Guardian Co-Deposition Controller Operating Manual
3.3.5 Readings Panel—Readings Mode
Click View >> Readings to see the readings display. See Figure 3-10 . The
readings display mode shows unfiltered channel (detector), sensor, and QCM
readings.
Figure 3-10 Readings Panel Readings Display
3.3.5.1 Channel Readings
Each channel uses either two or three measurements to calculate the channel
current signal. The measurements used are:
PMTCurOn: The first measurement cycle measures the detector current with
sensor bias voltage on. This is a measure of the deposition flux, plus any
background signal from ambient light or the sensor filament. This measurement
also includes any broadband emission from other process gases.
PMTCurOff: The second measurement cycle measures the PMT current with
sensor bias voltage off. With bias voltage off, no electron emission occurs. Hence,
this is a measure of only background light.
PMTCurGas: The third measurement cycle is used only with INFICON's gas
compensating (GC) sensor. The GC sensor includes an element that is not
exposed to materials being deposited. It measures only the emission caused by
gases, especially water vapor and nitrogen (plus any background light as explained
above).
When the three measurements are completed, the channel readings are displayed
as:
Flux - Gas: equals PMTCurOn minus PMTCurGas.