Hach-Lange SI794 P User Manual - Manual (Page 85)

85
Proportional action YP
Setpoint - Meas. value
Constant
YP =
* KC
with:
YP
Proportional action
TR Reset time [s]
TD Rate time [s]
KC Controller gain [%]
Constant 5 (for pH)
500 mV (for ORP)
100 %
50 %
Xw
(Process variables: pH/ (mV))
Co
nt
ro
lle
r
output
Y
K
C
= 500
% K
C
= 200
%
K
C
= 100
%
K
C
= 50
%
1 / (100) 2 / (200) 3 / (300) 4 / (400)
Proportional action (Gradient K
C
[%])
Deviation
Neutral zone (Y=0)
Tolerated deviation from desired value.
With the setting “1 pH”, for example, a deviation of ± 0.5 pH
from the desired value does not activate the controller.
5 / (500)
Controller equations
Controller output Y = YP + YPdt + TD
I action D action
dYP
dt
P action
1
TR