Advanced features – Fluid Components International MT91 Manual Operation User Manual
Page 13
CHAPTER 3 - OPERATION
FLUID COMPONENTS INTL
Doc. No. 003185 Rev. B
3 - 13
Model MT91 Multipoint Flowmeter
Ø To manually initiate the Calibration Test
1.
Go to menu level 3.3.1 (Diagnostics
Þ
Calibration Tests
Þ
Start Test). The sequence of screens A through E will
display.
2.
To view the results of the test, select 2=Display Results, from the menu level 3.3. If the system is unable to
balance out one of the sensing points, the suspect head will be noted with an x as shown in screen F. If no
balance problems occurred, screen F will not display. Finally, screen G displays the deviation of the stimulated
signals from the expected results.
Ø To set up the automatic Daily Calibration Test
w Set the time of day.
1.
Go to menu level 2.6 (Setup
Þ
Clock). Enter the hour and press ENTR.
2.
Enter the minutes and press ENTR.
3.
Press any key to exit.
w Set the time of the test.
1.
Go to menu level 3.4 (Diagnostics
Þ
Schedule Tests).
2.
Select 1=Calibration Drift.
3.
Enter the hour and press ENTR.
4.
Enter the minutes and press ENTR.
5.
Enter the seconds and press ENTR.
w Enable the automatic test.
1.
Go to menu level 3.4 (Diagnositcs
Þ
Schedule Tests).
2.
Select 2=Enable Auto Test.
3.
Select 1=Enable or 2=Disable.
With the daily automatic test enabled, the calibration drift test will run the same time each day. The normal outputs
will be driven to test values and the calculated results will be available for display.
Advanced Features
The remainder of this chapter contains topics that may not be applicable to every user of the flowmeter. In most case
the flowmeter will be ready for use straight out of the box. However, there may be instances where the advanced
features of the flowmeter may be needed. This section discusses how to correct for bias errors due to non-ideal
installations and how to communicate with the flowmeter through the serial port.
Flow Rate Correction Equation
The flow rate correction equation or corrector is used to bias the flow rate output. The correction equation contained
in the flowmeter allows the user to correct for bias errors due to non-ideal installation effects. The correction
equation is applied to the measured flow rate and then this corrected flow rate is used to drive the analog outputs and
manipulate the relays. The flow rate shown on the display is also the corrected value. The correction equation for
the flowmeter is shown below.
m
C
C
m
C
m
C
m
new
=
+
Ч
+
Ч
+
Ч
1
2
0
3
0
2
4
0
3
(
)
(
)
(
)
where
m
0
= Measured Flow Rate
C
i
= Correction Equation Coefficients (i = 1 through 4)
Default configuration is C
1
= 0, C
2
= 1, C
3
= 0, and C
4
= 0.
m
new
= Corrected Flow Rate