5. MAINTENANCE, ADJUSTMENTS AND CALIBRATIONS
Page 97
© 2008 DH Instruments, a Fluke Company
The calibration pressure standard is not required to apply precisely the nominal pressure value
of each calibration point as long as the exact value of the applied pressure is known. Best results are
obtained if the actual applied pressure is within 5 % of the recommended nominal point.
Table 15.
Calibration point sequence for A7M and A70M Q-RPTs
CALIBRATION
SEGMENT
POINT
NO.
POINT
[% OF SPAN]
1 0%*
2 25
%
3 50
%
4 75
%
Ascending
5 100
%
6 75
%
7 50
%
8 25
%
Descending
9 0%*
* AutoZ the RPM4-E-DWT with reservoir shut off valve close, TEST shut off valve open,
TEST port open.
5.3.5
RPT CALIBRATION USING CALTOOL FOR Q-RPTS SOFTWARE
To calibrate RPM4-E-DWT Q-RPTs using CalTool software, refer to Sections 5.3.1, 5.3.2,
5.3.3 and 5.3.4 in this manual and then refer to the CalTool for Q-RPTs Software Manual.
CalTool for Q-RPTs software and manual are supplied on the E-DWT-10000-AF Support
Disk and can be downloaded from
www.dhinstruments.com
.
5.3.6
EDITING AND VIEWING Q-RPT CALIBRATION INFORMATION
PURPOSE
View and/or edit Q-RPT calibration information fields including:
•
The calibration date
– This field is normally used to record the date on which the Q-RPT
is calibrated.
•
The value of absolute mode AutoZero P
offset
– Always 0 Pa. Not used in
RPM4-E-DWT A70M/A7M-AF.
•
The value of PA
– The pressure adder for the selected Q-RPT (see Section 5.3.1.1).
•
The value of PM
– The pressure multiplier for the selected Q-RPT (see Section 5.3.1.1).
OPERATION
As editing PA and PM values will change the calibration of the Q-RPTs, the edit function
should only be used by qualified personnel as part of the calibration process. Caution should be
taken to avoid accidental editing. A user level security system is available to control access (see
Section 3.9.5.5).
A new RPM4-E-DWT is delivered with PA and PM values set to zero and 1 for all ranges. This
does not mean that the RPM4-E-DWT has not been calibrated. In the original factory calibration,
privileged factory coefficients are used for calibration with the user PA and PM set to zero and 1.
