YOKOGAWA DPharp EJX***A Series User Manual

<4. Diagnostics>
4-7
IM 01C25T01-06EN
Table 4.3 Default Values of Limit Parameter
#
Parameter
Di󰀨erential pressure
transmitter
Flange
mounted
di󰀨erential
pressure
transmitter
Diaphragm
sealed di󰀨erential
pressure/
pressure
transmitter
Absolute
pressure
transmitter
Gauge
pressure
transmitter
Gauge/
Absol ute
pressure
transmitter
EJX110A
EJX115A
EJX130A
EJX120A EJX210A EJX118A
Note 1
EJX438A
EJX310A EJX430A
EJX440A
EJX510A
EJX530A
EJX610A
EJX630A
[1] Lim fDPmax 3 3 10000 10000 10000 10000 10000
[2] Lim fDPmin 0.3 0.3 0.3 0.3 0.3 0.3 0.3
[3] Lim fSPlmax 5 10000 10000 10000 10000 10000 10000
[4] Lim fSPlmin 0.5 0 0 0 0 0 0
[5] Lim fSPhmax 5 10000 10000 10000 10000 10000 10000
[6] Lim fSPhmin 0.5 0 0 0 0 0 0
[7] LimBlkFmax 0.6 10 10 10 10 10 10
[8] LimBlkFmin -0.6 -10 -10 -10 -10 -10 -10
[9]
Lim DPAvgmax
Note 2
1 1 1 1 1 1 1
[10]
Lim DPAvgmin
Note 2
0.05 0.2 -1 -1 0.05 0.05 0.05
Note 1: The default values are set for level measurement. If EJX118A is applied to ow measurement, enter the same value to Limit
parameter [1] to [10] as those of EJX110A.
Note 2: It indicates the threshold value for “ILBD over range” (refer to 4.2.2.5).
 H/L Blocking Detection
EJX di󰀨erential pressure transmitter enables
to detect both-, a high-, or low-pressure-side
blockage. The blockage degree characterized
by a comparison of high-pressure side and low-
pressure-side uctuation values, BlkF, is used to
detect it. The value changes within a range of –1
to +1. As BlkF approaches +1, the high-pressure-
side blockage progresses. On the other hand, if it
approaches –1, the low-pressure-side blockage
progresses.
1
0
1
0
F0404.ai
BlkF
Blockage detection for
high-pressure side
Threshold
Blockage Progress
BlkF
Blockage detection for
low-pressure side
Threshold
Blockage Progress
-1-1
Figure4.3 RelationbetweenBlockageProgress
andBlkF
The each threshold value to detect the high- or low-
pressure-side blockage is set to LimBlkFmax or
LimBlkFmin.
 A/B Blocking Detection
“A Blocking” and “B Blocking” indicates the result
estimated from blockage degree based on the
di󰀨erence of the high- and low-pressure-side
uctuation values. Ratio fDP, SQRT (fDP / Ref
fDP) is used to detect A/B blocking. Ref fDP is the
average value of the sum of squares of di󰀨erential
pressure uctuations under normal condition.
As the value of Ratio fDP exceeds the value of
Lim fDPmax, EJX gives basically an alarm of “A
Blocking”. On the other hand, if this value is below
the value of Lim fDPmin, EJX gives an alarm of “B
Blocking.
As a high- or low-pressure-side blockage
progresses, fDP increases. Therefore, “A Blocking”
with a di󰀨erential pressure transmitter indicates
that a single-side impulse line is plugged for a
di󰀨erential pressure transmitter. As the both-side
blockages progress simultaneously, fDP decreases.
Therefore, “B Blocking” with a di󰀨erential pressure
transmitter indicates that both-side impulse lines
are plugged.
NOTE
A single-side impulse line blockage may
generate “B blocking” under the condition where
the uctuation amplitude is much di󰀨erent
between high- and low-pressure sides.

YOKOGAWA DPharp EJX***A Series Specifications

General

Brand	YOKOGAWA
Model	DPharp EJX***A Series
Category	Transmitter
Language	English