ARCA 824 series, Руководство по эксплуатации

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8 Description ARCA Regler GmbH
18 / 46 Series 824 09.2018 / 1.0
Illustration 3: Functional description
8.1.1 Cam plate
The cam plate (24) of the positioner has three characteristics, which are
designed for a 60° angle of rotation equivalent to a 100% stroke or a 90°
angle of rotation for a 90° opening angle with rotary valves. For the basic
version, the linear curve (no. 1 in fig. 1) is provided normally. The on/off
curve (no. 2) and the equal percentage curve (no. 3) are also shown in
this diagram.
Figs. 1 and 2 show how these curves affect the flow rate of valves with
different opening characteristics. The linear curve (no. 1) linearly assigns
the valve stroke to the input signal, i.e. the input signal is mapped dir-
ectly to the valve stroke so that the effect of the valve's own opening
characteristic is retained. The use of the curves (nos. 2 & 3) offers the
possibility to change the effect of valve characteristics.
Fig. 1 Fig. 2 Fig. 3
Valve characteristics Flow characteristics Flow characteristics
depending on the input signal
with various cam plates
with various cam plates and
equal-percentage valve cone
depending on the input signal
with various cam plates and
linear valve cone depending
on the input signal