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FW-F018-P-M_v0404_01_EN.docx
3.3.3
EXPLANATION OF SETUP-MENU 2 - FLOW RATE
The settings for total and flow rate are entirely separate. In this way, different units of measurement
can be used for each e.g. cubic meters for total and liters for flow rate.
The display update time for flow rate is one second or more.
SETUP
FUNCTIONS
AND
VARIABLES
2
FLOW RATE
2.1
UNIT
SETUP
– 2.1 determines the measurement unit for flow rate.
The following units can be selected:
l/min
– l/hr – nm
3
/sec
– nm
3
/min
– nm
3
/hr
– nm
3
/day
– g/sec – g/min -
g/hr
– kg/sec – kg/min – kg/hr – kg/day – ton/min – ton/hr – ton/day –
gal/sec
– gal/min – gal/hr – gal/day – bbl/sec – bbl/min – bbl/hr –
bbl/day
– lb/sec – lb/min – lb/hr – lb/day – cf/sec – cf/min – cf/hr –
rev/sec
– rev/min – none – l/sec
Alteration of the measurement unit will have consequences for
operator and SETUP-level values. Please note that the K-factor has
to be adapted as well; the calculation is not done automatically.
2.2
DECIMALS
This setting determines for flow rate the number of digits following the
decimal point. The following can be selected:
0000000 - 111111.1 - 22222.22 - 3333.333.
2.3
K-FACTOR
With the K-factor, the flowmeter pulse signals are converted to a flow
rate.
The K-factor is based on the number of pulses generated by the
flowmeter per selected measurement unit (SETUP 2.1), for example
per liter. The more accurate the K-factor, the more accurate the
functioning of the system will be. For examples read SETUP 1.3.
2.4
DECIMALS K-FACTOR
This setting determines the number of decimals for the K-factor
(SETUP 2.3). The following can be selected:
0 - 1 - 2 - 3 - 4 - 5 - 6
Please note that this SETUP - influences the accuracy of the K-factor
indirectly. This setting has NO influence on the displayed number of
digits for "flow rate" (SETUP 2.2)!
2.5
CALCULATION
The flow rate is calculated by measuring the time between a number
of pulses, for example 10 pulses. The more pulses the more accurate
the flow rate will be. The maximum value is 255 pulses.
•
The lower the number of pulses, the higher the power consumption
of the F018-P will be (important for battery powered applications).
•
For low frequency applications (below 10Hz): do not program more
than 10 pulses else the update time will be very slow.
•
For high frequency application (above 1kHz) do program a value of
100 or more pulses.
2.6
CUT-OFF
With this setting, you determine a minimum flow requirement thresh-
hold, if during this time less than XXX-pulses (SETUP 2.5) are
generated, the flow rate will be displayed as zero.
The cut-off time has to be entered in seconds - maximum time is 999
seconds (about 15 minutes).
2.7
DAMPING
This sets the step-response time of the flow rate measurement. The
step-response time is the time it takes for the displayed value (and
thus the analog output value) to reach 63% of the final value.
For example, when the flow rate increases from 10 to 100 l/s and the
damping is set to 10 seconds, the analog output (and the displayed
value) will increase to: 10 + 0,63 x (100-10) = 66l/sec after 10 sec.
eventually it will display 100 l/sec.
