I [mA]
I 1
I 2
F1
F2
F
max
0
20
P1
P2
B0088
Fig. 28: Rate(frequency)-Current Diagram for Linear control
Plot a diagram similar to the one above – with values for
(I1, F1) and (I2, F2) – so that you can set the pump as
desired!
„Lower side band“
Using this type of processing, you can control a metering pump using the
current signal as shown in the diagram below.
However, you can also control two metering pumps for different feed
chemicals via a current signal (e.g. one acid pump and one alkali pump
using the signal of a pH sensor). To do this, connect the pumps electrically
in series.
The "Lower sideband" symbol appears in the LCD display. Below I1, the
pump works at a rate of F1 - above I2 it stops. Between I1 and I2 the
stroke rate varies between F1 and F2 in proportion to the signal current.
I [mA]
I 1
I 2
F2
F1
0
20
a)
b)
P1
P2
F
max
B0089
I [mA]
I 1
I 2
F1
0
20
P1
P2
F2
F
max
Fig. 29: Frequency-current diagram for a) Lower side band, b) Upper side band
„Upper side band“
Using this processing type, you can control a metering pump using the
current signal as shown in the diagram above.
However, you can also control two metering pumps for different feed
chemicals via a current signal (e.g. one acid pump and one alkali pump
using the signal of a pH sensor). To do this, connect the pumps electrically
in series.
The "Upper sideband" symbol appears in the LCD display. Below I1, the
pump is stationary - above I2 the pump works at rate F2. Between I1 and
I2 the stroke rate varies between F1 and F2 in proportion to the signal cur‐
rent.
Setting
51
