Druck ADTS 403F, Calibration Manual

Page: 26 / 40

Copyright 1996 Baker Hughes Company.
16 | ADTS 403/405 Calibration Manual–English
Chapter 4. Calibration
4.9 Calibration and Adjustment of the Combined Static and Pitot
Channels
Before starting this procedure carry out leak tests as detailed in Section 2. Set the unit to
measurement mode, main calibration, external pressure source and static (Ps) and pitot (Pt)
calibration as detailed in 4.1.
1. Connect calibration standard to the pitot output.
2. The display prompts for the date of calibration DD/MM/YY.
Note: The pressure values shown in the table are the values used and suggested by the
manufacturer, other values can be used.
3. Adjust calibration standard to the first pressure value in Table 4 - 3. Allow 1 minute for the unit
to stabilize.
4. The display prompts for [ACTUAL VALUE], enter the pressure value on the calibration
standard. Press [PRES] and the display prompts for the next pressure value.
5. Repeat (3) and (4) for pressure No. 2 to 8 in Table 4 - 3.
6. Press F4 [END PS], the unit automatically isolates the static channel from further pressures.
The unit calculates the change in zero (%FS) and span (%RD) from the previous, stored
static channel calibration values. The new calibration can be accepted or rejected. Once
accepted, the new values are stored replacing the previous values.
7. Repeat (3) and (4) for pressure No. 9 to 11 in Table 4 - 3; points 12 and 13 are used on the
1000 knot Pitot range sensors.
Note: A label on the front panel of the ADTS 403/405 shows the full-scale range of the Pitot
sensor.
8. Press F4 [END]. The unit calculates the change in zero (%FS) and span (%RD) from the
previous, stored pitot channel calibration values. The new calibration can be accepted or
rejected. Once accepted, the new values are stored replacing the previous values.
9. Adjust calibration standard to atmospheric pressure. Using a 3 mm AF hexagonal key (Allen
key), turn the captive, calibration screw fully clockwise.
10. To verify the new calibration, carry-out a calibration check of the combined pitot and static
channels as detailed in 4.5 starting at (2).
11. Before leaving Calibration mode, the ADTS prompts to “Back up New Calibration Data?”.
Answering 'YES' will back up the calibration data, for both controllers, in the motherboard.
After completion of all main calibration procedures, carry out the procedures detailed in 4.9.
4.10 Completion
After completion of all main calibration procedures, carry out the following:
1. Make sure the calibration standard and the unit are at atmospheric pressure. Disconnect the
calibration standard from the unit.
2. Fit a new calibration label over the calibration screw.
4.11 Rate Calibration
Rate calibration should only be carried out if the rate accuracy is suspect. The accuracy of
measurement and control is not affected by a rate calibration and the calibration date does not
change after using this facility.
CAUTION
The static channel transducer will be over-pressurized and
probably damaged if further pressures in Table 3 are applied.