KROHNE IFC 090 Converter EN - Manual (Page 63)

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If you need to return your flowmeter to Krohne,
please refer to last but one page of these Instructions !
Example
Full-scale range Q
100%
= 200 m 3 /hr (Fct. 1.01)
Meter size DN = 80 mm = 3“ (Fct. 3.02)
Current at Q
0%
I
0%
= 4 mA
Q
100%
I
100%
= 20 mA
}
(Fct. 1.05)
Pulses at Q
100%
P
100%
= 280 pulses/hr (Fct. 1.06)
Primary head constant GK = 3.571 (see nameplate)
Constant (V in m3)
(t in hr) K = 7074 (see Table)
(DN in mm)
Calculation of “ X ” and position of “ Y ”
X =
Q
100%
x K
=
200 x 7074
= 61.905
GK x DN 2 3.571 x 80 x 80
Y = 80, position of switch Y, see front panel GS 8A
(comes closest to X value and is smaller than X).
Calculation of setpoint readings I and f
I = I
0%
+
Y
(I
100%
- I
0%
) = 4 mA +
40
(20mA - 4mA) = 14.3 mA
X 61.905
Deviations are permissible between 14.1 and 14.6 mA (equivalent to ± 1.5 %).
f =
Y
x P
100%
=
40
x pulses / hr = 129.2 pulses/hr
X 61.905
Deviations are permissible between 127.3 and 131.1 pulses/hr (equivalent to ± 1.5 %).