Agilent Technologies Eyesys Mini-B/A, Instruction Manual

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Eyesys Mini-B/A Gauge Controller
13
The following chart is derived from the above formula. Output voltage is pegged to the
extremes under the following conditions (see “Error Conditions” on page 11):
NOTE
Pressure voltage is not available with the RS422 option.
Gas Correction
Gas Correction Factor Table
For manual use of the table, divide the pressure reading by the gas correction factor.
Gas correction factor tables are only reproduced for the convenience of the user and do not
imply that use with other gases will be safe with hot filament gauge controllers. Table 8 on
page 14 lists relative gauge gas correction factors for various gases. The values are derived
by empirical methods substantiated by measurements reported in literature. This table was
compiled and published by Robert L. Summers of Lewis Research Center, NASA Technical
Note TND-5285, National Aeronautics and Space Administration, Washington, DC,
June 1969.
To automatically convert readings of the Mini-BA gauge, enter the relative gas correction
constant via the appropriate Serial Communication command (see Serial Communication
option). The current gas correction factor can be polled from the gauge by use of a separate
command. The gauge will divide the result by the gas correction constant:
Corrected Pressure = Raw Pressure / Gas Correction Constant
The adjusted value is applied to the display, signal output and serial communication
pressure outputs.
To calculate pressure, given volts: Pressure = 10
(Volts-8)
x1.33 for Pascal
10
(Volts-10)
for Torr
10
(Volts-10)
x1.33 for mbar
Condition Volts
Under pressure 0.5 V
Emission OFF 10 V
Error 5, 6, 8 or 9 10 V