MKS 109030111, Инструкция по эксплуатации

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5 Operation
26
Series 903 Cold Cathode Vacuum Sensor
Instruction Manual - #109030026
5.3.2 Equation for Converting Voltage to Pressure
The following equation converts the 903 Sensor voltage reading “V” to a pressure reading “P” when
using air or nitrogen. The voltage must be within the domain of the equation or an incorrect
pressure reading will result.
P = 10
( V-K )
Where,
P is in Torr, mbar, microns, or Pascal (depending on K)
V is in volts for 0.5 + V + 7.7
K = 10.000 for Torr, 9.875 for mbar, 7.000 for microns, 7.875 for Pascal.
5.3.3 Vacuum Indicator
Connect a digital voltmeter to the Common tip jack and the Vacuum Indicator tip jack on the 903
Sensor. See Figure 5-3. Adjust the potentiometer with a small screwdriver until the voltage reading
coincides with the desired Vacuum Indicator pressure. This pressure is shown on the graph in Figure
5-2, or is calculated from the equation above.
When the set point LED is ON, the measured pressure is below the Vacuum Indicator value. When
the LED is OFF, the measured pressure is above the Vacuum Indicator value.
If the high voltage is started in high vacuum and the sensor discharge has not yet begun, the 903
Sensor will indicate too low of a reading, possibly turning ON the Vacuum Indicator LED.
Figure 5-3: Vacuum Indicator Adjustments and LED