Gas Mixed Flow Alarm - Oval ALTI mass CA00A Instructions Manual

9.17 Gas Mixed Flow Alarm Function
If gases exist in large quantities in the process fluid, it is impossible to make accurate flow measurement.
This feature, if correctly set up, detects gases entrapped in the fluid, indicates a slug flow alarm, clamps
the flow signal at 0, and provides a status output telling the operator the alarm event. (If you want to use
this function, set the higher limit density value of slug flow to 10 (default) and the lower limit density value
of slug flow to 0 (default). This function then remains disabled.) The setup procedure of slug flow function
is outlined below.
(1) Setup procedure
Ensure positive settings of individual items.
① Lower limit density of slug flow (Slug Low) (See 9.2.3 Transition chart (2) [No. 2-2-3].)
Upon detection of density smaller than this setting, the circuitry interprets it as slug flow
and starts analysis.
Set a value small enough with respect to the density expected for the fluid of interest.
② Higher limit density of slug flow (Slug High) (See 9.2.4 Transition chart (2) [No. 2-2-4].)
Upon detection of density larger than this setting, the circuitry interprets it as an error and
starts analysis.
Set a value large enough with respect to the density expected for the fluid of interest.
③ Slug flow identification time (Slug Duration) (See 9.2.5 Transition chart (2) [No. 2-2-5].)
It is the time required for the circuitry to identify the slug flow being outside the slug flow
high/low limit and to issue a slug flow alarm (sec). Until this slug flow identification time
expires, it retains the most recent and properly measured value. After the expiration of this
preset time, the flowrate becomes 0.
④ If you want to assign this slug flow alarm in the status output function to the status output,
setting the following is required: (For detail of this output function, see 9.14 Status Output
Function.)
・Status output function assignment: Error Status (See 9.2.5 Transition chart (2) [No. 2-4-
5-1].)
・Slug flow error select: On (See 9.2.5 Transition chart (4) [No. 2-4-5-2-7].)
・Active output of status output: Off Active or On Active (See 9.2.5 Transition chart (4)
[No. 2-4-5-3].)
NOTE: For this function, the setting change is disabled
in Write Protect mode (refer to section 9.2).
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