L-770HP--E
7
（
）
Slug duration (duration of gas multi-phase flow identification)
This is the duration [sec] from the point where the density value deviates from the higher / lower limit
value of gas multi-phase flow until the gas multi-phase flow alarm is set.
Until the density value deviates from the higher / lower limit value of gas multi-phase flow and Slug
duration expires, the flowrate maintains the last flowrate value which is normally measured.
After Slug duration expires, the flowrate becomes 0.
（
）
In the case that assigning of the gas multi-phase flow alarm of status output function to the status
output is required; execute assigning to the status output according to
“
. Status output function
”
.
（
）
Set the pulse / analog output selection (Lower / Upper) for Slug Alm. by using the parameter (Slug
flow output). With the Lower setting, the flowrate analog output will be mA and the flowrate pulse
output will be 0Hz upon the occurrence of alarm.
With the Upper setting, the flowrate analog output will be .mA and the flowrate pulse output will
be the frequency which is set by
“
Pulse upscale freq
”
.
■ Example of settings and operations
・
Slug low limit (lower limit density value of gas multi-phase flow): 0. [g/mL]
・
Slug high limit (higher limit density value of gas multi-phase flow): .0 [g/mL]
・
Slug duration (duration of gas multi-phase flow identification): 0 [sec]
Time
Time
"Higher limit density [2.0]"
"Lower limit density [0.5]"
Slug flow
alarm active
Slug flow
under
test
Slug flow
alarm active
Slug flow
under
test
Density
2.0
0.5
0
0
Slug flow identifi- 10sec
cation time
Slug flow identifi- 10sec
cation time
Flowrate with slug flow alarm active
Flowrate with slug flow alarm inactive
Density fell below
high limit value;
slug flow test
starts with flow
data retained.
Alarm canceled
as density
exceeded low
limit value.
Density fell below low limit value;
as slug flow test duration expires,
a slug flow alarm is issued with
flowrate clamped at 0.
Density exceeded high limit value;
as slug flow test duration expires,
a slug flow alarm is issued with
flowrate clamped at 0.
Density exceeded
high limit value;
slug flow test
starts with flow
data retained.
Alarm canceled
as density fell
below high limit
value.
Density [g/mL]
Flowrate [kg/min]
