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Setpoint
delta
Cl
mg/L
time
Proportional dosing
Relay on
Relay off
The output will be proportional with chlorine if the read value is between those limits.
Example: For PCA310 - PCA330 if the 0.0 to 1.0 V recorder output has been selected, the operator
can select 0.0 V to correspond to a concentration of 3.00 mg/L (Min. Rec. setting) and 1.0 V to
correspond to a concentration of 4.50 mg/L (Max. Rec. setting).
For PCA340 if the 0.0 to 20.0 mA recorder output has been selected, the operator can select
0.0 mA to correspond to a concentration of 3.00 mg/L (Min. Rec. setting) and 20.0 mA to correspond to
a concentration of 4.50 mg/L (Max. Rec. setting).
The full scale span of the recorder would then be 1.5 mg/L, yielding a magnified view of the
3.00 to 4.50 mg/L concentration range on the recorder.
The analog output limits can be quickly consulted in one of the chlorine measuring panels.
CHLORINE DOSING
The PCA310 - PCA340 analyzers contain a simple proportional dosing algorithm. Proportional dosing
establishes and maintains a controlled and consistent concentration level.
The analyzer has a relay for chlorine dosing and also the 4-20 mA output could be configured as a
dosing outputs.
The equation for determining the time for relay on is:
dosing time = (set value - measured value)*Period/Delta
The analog output will have the value:
analog output [mA] = 4 + 16 * dosing time/Period [mA]
Note: If the measured concentration is lower than setpoint minus delta, the dosing will be
continuous until the next measurement is taken (one period).
CHLORINE SETTINGS
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