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RPM4-AD™ OPERATION AND MAINTENANCE MANUAL
© 2005-2007 DH Instruments, a Fluke Company
Page 122
The Q-RPTs of RPM4-AD A160K/A160K that are used in parallel measurement mode (see
Section 3.2.5) may be run through the calibration sequence simultaneously but must be
adjusted separately. PA and PM for the Hi and Lo Q-RPT need to be determined and set
individually. Therefore, data to be used in determining calibration coefficients cannot be
taken in parallel mode since parallel mode displays the average measurement of the two
Q-RPTs. To calibrate the Q-RPTs of RPM4-AD A160K/A160K simultaneously, make the Hi
Q-RPT active, use the [RPT], <4RPT> (see Section 3.3.6.4) function to display the Lo Q-
RPT measurement on the display bottom line and use [SPECIAL], <4SDS> to OPEN SDS
on the Lo Q-RPT (see Section 3.5.4.1).
OPERATION
The typical procedure for calibrating a Q-RPT is:
Set-up and prepare the RPM4-AD for calibration (see Sections 5.2.2, 5.2.3).
Use
the
[RANGE]
function key to select the Q-RPT to be calibrated (see Section 3.3.1).
RPM4-AD A160K/A160K: the Q-RPTs of the RPM4-AD A160K/A160K have the same
range and can be calibrated simultaneously. To do so, make the Hi Q-RPT active, use
[RPT], <4RPT>
to display the Lo Q-RPT measurement on the display bottom line (see
Section 3.3.6.4) and use
[SPECIAL]
,
<4SDS>
,
<1temp open/close>
to OPEN SDS on
the Lo Q-RPT (see Section 3.5.4.1).
RPM4-AD A350K/A160K: the Hi and Lo Q-RPT must be calibrated completely separately.
Use
[HEAD]
to set the HEAD to zero (see Section 3.3.7).
Use
[UNIT]
to set the desired pressure unit of measure (not an air data unit) (see Section
3.3.2).
Use
[MODE]
to set absolute pressure measurement mode (see Section 3.3.3).
Use
[SPECIAL]
,
<1AutoZ>
to access the AutoZ function (see Section 3.5.1).
Turn AutoZ ON if it is left ON in normal RPM4-AD operation.
Use
[SPECIAL]
,
<8cal>
,
<1Hi RPT>
or
<2Lo RPT>
,
<1view>
, to read and record the
current values of PA, PM and P
offset
for the Q-RPT to be calibrated.
Exercise the Q-RPT(s) and run the recommended calibration point sequence (see
Section 5.2.4). Record the pressure applied by the standard and the RPM4-AD Q-RPT
reading at each calibration point (record output of both Hi and Lo Q-RPT is calibrating both
Q-RPTs of RPM4 A160K/A160K simultaneously. Dwell at least 60 seconds at each point
after setting the reference pressure to allow full stabilization. The data recorded is the
“as received” data for this calibration.
Enter the calibration pressures and RPM4-AD readings into a spreadsheet. Calculate
the “non-corrected” RPM4-AD readings by backing out the PA, PM and P
offset
recorded in
Steps and above, following:
non-corrected reading = ((corrected reading - PA)/PM ) + P
offset
Perform a linear regression to find the offset and slope that best fit the non-corrected
RPM4-AD readings to the calibration standard pressures. The offset is the new value of
PA, the slope is the new value of PM.
Press
[SPECIAL]
,
<8Cal>
,
<1Hi RPT>
or
<2Lo RPT>
,
<2edit>
and write the new
calibration date and the new values of PA and PM for the Q-RPT(s) calibrated. Set the
value of P
offset
to zero (see Section 5.2.7).
Calculate as left data for the calibration if desired following:
as left reading = (non-corrected reading • new PM) + new PA
Perform additional verification pressure runs as desired.