Azbil JTD910S User Manual

A-21
Appendix A Maintenance and Troubleshooting of this Device
x
ma
x
x
min
Index value
Minimum value of
one-side clogging
simulation test
Maximum value of
both-side clogging
simulation test
Maximum value
under normal
operating conditions
Minimum value
under normal
operating conditions
Index value range
under the normal
operating conditions
Threshold value
(High limit)
Threshold value
(Low limit)
After determining the threshold value, follow the steps below to set the alarm and start the
diagnosis.

Procedure

(1) Execute Reset Press Freq Index.
(2) Set Press Freq Index Low Limit to the determined threshold value (lower limit).
(3) Set Press Freq Index High Limit to the determined threshold value (upper limit).
(4) Set Press Freq Index Alarm Use “Enabled (High and Low)” (upper and lower limits).
With these settings, when the index value is outside the normal range and approaches the value
with simulated clogging, the alarm is activated.
A3-4-6 Parameter adjustment (for both-side clogging diagnosis)
If both-side clogging diagnosis is judged to be not possible, the data that is collected under normal
operating conditions (section A3-4-2) and when there is simulated clogging (section A3-4-3) can
be analyzed and the parameters adjusted. The reason why diagnosis cannot be performed is that
the index value—even under normal operating conditions—is similar to or smaller than that when
there is clogging, so the normal and clogged states cannot be distinguished. There are two primary
causes leading for this situation.
• A large amount of variation of the index under normal conditions
• A small variation of the index when there is clogging
This situation may be improved by adjusting the parameters of the pressure frequency index
diagnosis. The following describes the two cases.
(A) Variation of the index under normal operating conditions is large.
In this case, although the value of the index is small with simulated clogging, variation in the index
is large under normal conditions, so the index value can be close to or equivalent to its value with
clogging even when there is no clogging, as shown in the figure below.

Azbil JTD910S Specifications

General

Brand	Azbil
Model	JTD910S
Category	Transmitter
Language	English