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pH control settings
Parameter
Description
Setpoint pH
The desired pH value of the swimming pool water.
It is recommended that you aim for a pH value of 7.2 since water disinfection is most effective at this
level.
Lower Alarm pH
The lower alarm threshold of the pH value. As soon as the pH value falls below the entered level, an
alarm is output.
The lower limit should lie 0.4 pH below the setpoint.
Upper Alarm pH
The upper alarm threshold of the pH value. As soon as the pH value rises above the entered level, an
alarm is output.
The upper limit should lie 0.4 pH above the setpoint.
Max. Dos. Time pH
The maximum duration for which an agent to raise or lower the pH value is dosed. If the set time is
exceeded, an alarm is output and dosing of the agent is stopped.
p-Range pH
The p-range setting. The p-range defines the response speed of the controller.
As a rule:
The smaller the percentage, the more product will be dosed.
Advantage: the setpoint can be reached quickly.
Disadvantage: the setpoint may not only be reached but may actually be exceeded.
The larger the percentage, the less product will be dosed.
Advantage: the setpoint is reached and is not exceeded.
Disadvantage: the setpoint is reached more slowly.
Min. On-time
Minimum time for which the dosing pump is switched on. If the current deviation of the pH value
requires a dosing time that is less than the set on time, dosing still takes place for the set on time.
Dead Zone pH
The Dead Zone for the pH controller is set here. As long as the control deviation between setpoint and
actual value lies within the Dead Zone, control remains inactive, i.e. there is no dosing. The control only
starts dosing again when the control deviation moves outside the Dead Zone. When the reading moves
(back) into the Dead Zone, the control remains active until the actual value reaches the setpoint.
Dos. Period pH
The Dosing Period (or dosing cycle) for pH control is programmed here. Since the control uses pulse
width modulation, the dosing period (i.e. the sum of the switched-on and switched-off time of the dosing
relay) remains constant.
The actual dosing rate is obtained from the variation in the ratio between the switched-on time and the
switched-off time.
Dos. Direction pH
D-
Only a dosing device to reduce pH is connected.
The pH control operates in one direction only to reduce the pH level.
D+
Only a dosing device to increase pH is connected.
The pH control operates in one direction only to increase the pH level.
(D+/D-)
Two dosing devices are connected to reduce or increase pH.
The pH control operates in both directions to reduce or increase the pH level.
pH electrode calibration
The Pool Relax pH electrode must be calibrated once every three months to compensate for any deviations in its measurement
behaviour. The electrode must be replaced once a year.
These maintenance and replacement intervals absolutely must be complied with to ensure that measurements are correct and that
water quality is at its best.
As an example, the procedure for a 1-point calibration of the pH electrode is described here.
The 1-point calibration takes place in the main menu (customer). In this menu, select the Measuring & Control menu followed by the
Calibration menu.