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V. Setting of parameters and operation mechanism
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Setting of parameters and operation mechanism (PH model)
•
Operation mechanism
•
The stroke rate of the pump is represented by the real line in the figure above. The range of proportional control
is called proportional band (PB). The spm value indicates the max. stroke rate of the pump. In the example
above, the stroke rate is fixed at 300 spm for the pH values at or lower than 2.50. The PB value is assumed to be
added to the SET value, which increases the stroke rate in the figure above as the pH measurement decreases.
For example, the stroke rate for the measured value 4.00 pH stands at 120 spm.
•
The parameters are set before shipment from the plant. Set them to the required values in accordance with the
application purpose before use.
•
If the measurements exceed the value set for Lo or Hi, the alarm function runs with display and/or alarm output
(optional function). The values for Lo and Hi can be set as required upon the condition, however, a setting of
Lo>Hi should be avoided.
•
When the measured value is at or lower than the Lo set value:
The display ALM is lit and Lo flashes.
spm
360
270
300
180
90
0
2
4
5
6 7 8
10
12
14
pH
Parameter
q
SET
w
PB
e
spm
Lo
Hi
5.00pH
-2.50pH
300spm
2.00pH
12.00pH
e
w
q
2.5
-2.50
MAN
ZERO SPAN
AUTO
°
C
ALM
SET
PB
spm
pH
Hi
Lo
