Swan Analytical Instruments A-85.119.010, Manual

Page: 26 / 131

3 - Structure and Function
Hardware
3.2.1
消 毒 剂
Dosing devices for DIS and pH
regulation
There are different devices used to regulate the concentration
of treatment chemicals in water.
Solenoid
dosing pump
with external
control
P
Pump intensity is controlled by
higher/lower pulse frequency,
depending on how far the actual
value (pH, ppm) is from the
target value (setpoint).
Power con-
trolled pump
(do NOT con-
nect solenoid
dosing
pumps this
way!)
P
Regulates by switching the
pump/valve ON and OFF.
To optimize results, set the
parameters
Hysteresis and
Delay . Even better results are
achieved with the Time
proportional control, parameters
Cycle Time and Response Time .
Solenoid
valve
S
Valve normally closed, opens
when triggered by AMI
instrument.
More satisfactory results are
achieved with the
Time
proportional control, parameters
Cycle Time and Response Time .
Motor valve
M
Motor operated valve for
controlled opening and closing.
One relay used for opening, the
other for closing the valve, i.e.
with the 2 relay contacts
available, only one motor valve
can be controlled.
18 AMI Trides
Operator’s Manual, A-96.250.101