Druck ADTS 403F, Calibration Manual

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Copyright 1996 Baker Hughes Company.
English–ADTS 403/405 Calibration Manual | 13
Main Calibration
This selection uses the pressure and vacuum controllers of the ADTS to generate the
required pressures for calibration. The necessary AIM values and RATE of pressure change
can be set. A calibration standard of the required accuracy, connected to the output ports,
measures the pitot and static channels.
This is the recommended method of calibration.
• External:
This selection uses a deadweight tester (or similar calibration standard) to generate the
pressure and vacuum for calibration. The ADTS, in measure mode, displays the applied
pressure and vacuum in the pitot and static channels.
4.6.3 Select Calibration Mode
Select calibration mode from:
•
Static (Ps) channel - absolute
This mode calibrates the static (Ps) channel.
Connect the calibration standard to the static (Ps) output on the front panel. Fit the blank on the
pitot (Pt) output.
•
Pitot (Pt) channel - absolute
This mode calibrates the pitot (Pt) channel, using an absolute pressure, calibration standard.
Connect the calibration standard to the pitot (Pt) output on the front panel.
Fit the blank on the Static (Ps) output.
•
Combined Static (Ps) and Pitot (Pt) channel - absolute
This mode enables combined calibration of static (Ps) and pitot (Pt) channels to minimize
calibration time and errors due to calibration standard non-repeatability.
Connect the calibration standard to the pitot (Pt) output on the front panel.
Fit the blank on the Static (Ps) output.
When using combined static (Ps) and pitot (Pt) calibration, the pressures must be applied in
ascending order starting from the lowest pressure. Each entered exact pressure will be used as
a calibration point for both static (Ps) and pitot (Pt) until [END CAL] is selected. At that point the
static (Ps) calibration will be completed, a valve will close to protect the static (Ps) channel and
the remaining points will be used for the pitot (Pt) channel only.
Calibration Points
1. Following calibration initialization, the calibration entry screen appears, showing the present
measured static (Ps) and pitot (Pt) values.
2. Two functions are common to INTERNAL and EXTERNAL pressure source:
[ACTUAL VALUE]
• This allows the actual value of the pressure, applied by or measured by the calibration
standard, to be entered. The pressure must be allowed to stabilize before entering the value.
The minimum number of calibration points is two.
• There is no upper limit to the number of points that may be entered. For specification
accuracies to be achieved, Druck recommend a minimum of five points on static (Ps) with a
further three on pitot (Pt) if both are calibrated together.
CAUTION
Unless the [END CAL] instruction is given, the static PS sensor will
be over-pressured with pitot PT values.