Emerson MICRO MOTION 1500, Руководство по конфигурации и использованию, Страница: 90 / 282

80 Micro Motion Series 1000 and Series 2000 Transmitters
Optional Configuration
1. Referring to the totalizer management flowchart in Figure 7-3,
Scroll
to the appropriate
display screen:
• To change the setpoint for an event defined on mass total,
Scroll
to the mass total screen.
• To change the setpoint for an event defined on volume total, Scroll to the volume total
screen.
2. Select .
3. Enter the new setpoint value. See Section 2.4.5 for instructions on entering floating-point
values with the display.
8.12 Configuring slug flow limits and duration
Slugs – gas in a liquid process or liquid in a gas process – occasionally appear in
some applications. The presence of slugs can significantly affect the process density
reading. The slug flow parameters can help the transmitter suppress extreme
changes in process variables, and can also be used to identify process conditions that
require correction.
Slug flow parameters are as follows:
• Low slug flow limit – the point below which a condition of slug flow will exist. Typically, this
is the lowest density point in your process’s normal density range. Default value is 0.0 g/cm
3
;
range is 0.0–10.0 g/cm
3
.
• High slug flow limit – the point above which a condition of slug flow will exist. Typically, this
is the highest density point in your process’s normal density range. Default value is 5.0 g/cm
3
;
range is 0.0–10.0 g/cm
3
.
• Slug flow duration – the number of seconds the transmitter waits for a slug flow condition
( outside the slug flow limits) to return to normal ( inside the slug flow limits). Default value is
0.0 seconds; range is 0.0–60.0 seconds
If the transmitter detects slug flow:
• A slug flow alarm is posted immediately.
• During the slug duration period, the transmitter holds the mass flow rate at the last measured
pre-slug value, independent of the mass flow rate measured by the sensor. All outputs that
report mass flow rate and all internal calculations that include mass flow rate will use this
value.
• If slugs are still present after the slug duration period expires, the transmitter forces the mass
flow rate to 0, independent of the mass flow rate measured by the sensor. All outputs that
report mass flow rate and all internal calculations that include mass flow rate will use 0.
• When process density returns to a value within the slug flow limits, the slug flow alarm is
cleared and the mass flow rate reverts to the actual measured value.
Note: This functionality is not available via the display menus.
Note: The slug flow limits must be entered in g/cm
3
, even if another unit has been configured for
density. Slug flow duration is entered in seconds.
Note: Raising the low slug flow limit or lowering the high slug flow limit will increase the possibility
of slug flow conditions. Conversely, lowering the low slug flow limit or raising the high slug flow limit
will decrease the possibility of slug flow conditions.
• Model 1500 AN
• Model 1700 AN
• Model 1700 IS
• Model 2500 CIO
• Model 2700 AN
• Model 2700 IS
• Model 2700 CIO