A-16
Appendix A Maintenance and Troubleshooting of this Device
A3-4 Configuration procedures
This section describes the configuration procedures in order.
A3-4-1 Preparation
Before starting configuration, initialize the parameters.
Procedure
(1) Set Press Freq Index Sensor Selection to “DP, 120 ms.”
(2) Set Press Freq Filter Constant to “0.15.”
(3) Set Press Freq Calc PV High Limit to “Upper Range Value.”
(4) Set Press Freq Calc PV Low Limit to “Lower Range Value.”
(5) Set Press Freq Index Alarm Use to “Disabled” (operation off).
A3-4-2 Acquisition of the index values under normal operating conditions
Obtain the index value under normal operating conditions without clogging in the connecting
pipe. The collected pressure frequency index and standard deviation values are used to judge the
possibility of diagnosis and to adjust the parameters in later steps.
Procedure
(1) Check that the connecting pipe is operating normally. When a valve such as a manifold valve is
attached to the connecting pipe, check that the pressure can be measured.
(2) Execute Reset Press Freq Index and Reset Standard Deviation. Note that after Reset Press Freq
Index is executed, the correct values for Pressure Frequency Index, Press Freq Index Min, and
Press Freq Index Max cannot be obtained for a short period. After Reset Press Freq Index has
been executed, wait until the first index calculation is completed.
(3) Wait for at least 30 minutes, and if possible one hour.
(4) Obtain the values of Pressure Frequency Index, Press Freq Index Min, Press Freq Index Max,
and the process variable, and record them.
(5) Obtain the values of Standard Deviation, Standard Deviation Min, and Standard Deviation Max
as reference values, and record them.
If there are multiple operating conditions, perform the steps above under as many conditions as
possible and collect the data. The reason for this is that the pressure frequency index value may
vary depending on the operating conditions, even when the process state is normal. Covering
as many conditions as possible will enable judging of the possibility of diagnosis and parameter
adjustment to be carried out more reliably.
A3-4-3 Clogging simulation test
If a valve such as a manifold valve is connected to the connecting pipe, the valve can be utilized to
conduct the clogging simulation test. The pressure frequency index and standard deviation values
that are collected in the clogging simulation state are used to judge the possibility of diagnosis and
to adjust the parameters in later steps.
Three kinds of clogging simulation test are conducted. The both-side clogging simulation test, in
which valves on both the high pressure and low pressure sides are closed, and the one-side clogging
simulation test, in which the valve on one side only is closed, are conducted. Two kinds of one-side
clogging simulation test are conducted, one where the high pressure side is closed, and the other
where the low pressure side is closed.
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