Xylem Magflux Electromagnetic Flow Meter User Manual
Page 69
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Electromagnetic Flow Meter
FW: 842018/842009
If a required volume betwen pulses is not contained in the above steps,
for example for a pre-set to a sampler, use the batch counter option.
The relays are limited to a minimum and a maximum of pulses pr. hour
depending on the 20 mA scale and the on-time of the relay in milli-
seconds.
DO 1 (Opto Relay)
The maximum limit is 500 pulses pr sec at 1 ms pulse length.
The formula for the minimum flow unit pr pulses is:
(flow at 20mA) x (pulse delay in mSec) / 1800000
Example: Min. flow unit/pulses for DN 100 max. flow 300 m
3
/h ?
Minimum flow unit pr pulses = 300 m
3
x 100 mSec / 1800000 =
0,016 m
3
which is rounded to 0,1 m
3
by the MagFlux.
The formula for the maximum flow unit pr pulses is:
(flow at 20mA)
Example: DN 100 max. flow 300 m
3
/h ?
Maximum flow unit pr pulses = 300 m
3
DO 2 (Mechanical Relay)
The maximum limit is 120 pulses pr hour.
The formula for minimum flow unit pr pulses is:
(flow at 20mA) / 120
Example: DN 100 max. flow 300 m
3
/h ?
Minimum flow unit pr pulses = 300 / 120 = 2,5 m
3
which is rounded to
10 m
3
by the MagFlux.
The formula for maximum flow unit pr pulses is:
(flow at 20mA)
Example: DN 100 max. flow 300 m3/h ?
Maximum flow unit pr pulses = 300 m
3