Burkert Type 8620 - Manual (Page 123)

mxCONTROL Type 8620
Page 123
14.6.2 Process-value-proportional dosing (OPEN_PROP)
This module calculates the control output proportionally to the scaled process value. The module can
be used, e.g. for the Dosing of oxygen-absorbing substances if the temperature impact can be
neglected and dosing shall be done only in proportion to the feed water flow.
These
modules are
explained
below.
Figure 60: OPEN_PROP
Dosing control
The dosing control calculates the output signal only in dependence on the process value (here: flow).
The actual flow value is converted into a scaled flow 0…100% whereby 0% corresponds to the low
scaling value Scal- and 100% to the high scaling value Scal+ of the process value input. The scaled
process value is provided as control output.
Control output = a
with a … Process value (scaled value)
Figure 61:
Dosing control (OPEN_PROP).
Control output limitation
Please refer to the description in section "Control output limitation" in chapter 14.6.1.