Rosemount 3491, Справочное руководство, Страница: 90 / 152

Reference Manual
00809-0100-4841, Rev. AA
May 2007
Rosemount 3490 Series
4-58
Pumped Volume Totalising
(Totaliser Option - see Table 4-12 on page 4-45)
This function may be used to determine the total throughput of a well.
NOTE:
The "Totaliser" Wizard can be used to set-up Pumped Volume Totalising - see
Section “Totaliser Wizard“ on page 4-67.
The 3490 Series Control Unit monitors what goes into the well when no
pumps are running. It calculates the Rate of Change (RoC) of PV every 5
seconds and then converts it to a Rate of Change per minute for displaying as
parameter D809.
When a pump is turned on, the 3490 Series Control Unit assumes that the
rate of inflow remains the same as it was just before starting the pumps. The
RoC value (D809) is frozen whilst the pumps are on, i.e. when any Assist or
Standby relay is energised.
In order to totalise pumped volume, the PV value (D800) must be in volume
units so that the RoC value is in volume units per minute. The 3490 Series
Control Unit integrates this volume every second and increments the totaliser
for every integer unit.
Therefore, if the RoC value (D809) is 12m
3
per minute and the total factor
(P530) is set to 1.0 (m
3
), the Totaliser Count (D828) will increment every
5 seconds (1/12th of a minute = 5 seconds).
Menu: MAIN MENU / SETUP / [CONTROL UNIT /] OUTPUT / TOTALISER
P530 Total factor (Factor default is 0.0)
One count is added to the Totaliser Count (D828) for a quantity of liquid as
defined by this parameter.
P531 Total units (Factory default is "None")
Pumped Volume Totalising is selected by the totaliser units (P531) being set
to "PVol". (This parameter defines the display units for parameter D828).
NOTE:
For other associated parameters, see “About Totalising On Model 3491“ on
page 4-63.