1
Filtration
The water is drawn in through the skimmer and sent by the filtration pump to the filter, which retains the suspended impurities.
Swimming pool systems
Centurio POOL
Ideal for keeping all the pool parameters under control, including free, total and combined chlorine, pH and Redox, volume of make-up and discharged water, dechlorination of the discharge, and dosing of flocculant and algicide. The worthy successor to the MAX5.
- Up to 10 measuring channels
- Free, total and combined chlorine
- Measured make-up and discharge
- Touch screen and 6 timers
- Ethernet, Wi-Fi and Modbus as standard
10Measuring channels
6Timed outputs
8Alarm inputs
2Water meters: make-up and discharge
How it works
The treatment circuit of a swimming pool
The pool water circulates continuously between the pool and the plant room, where it is filtered, analysed and disinfected before being returned.
Insight: swimming pool water →
2
Measurement
A water sample flows through the probe holder of the panel, where pH and free chlorine are measured continuously.
3
pH control
The controller regulates pH as a priority: the pump doses the corrector until the set value is reached.
4
Chlorine dosing
With the pH at the correct values, hypochlorite is dosed, at a flow rate that is progressively reduced as the set point is approached.
5
Return to the pool
The filtered and disinfected water is returned to the pool through the return inlets.
6
Make-up
Water lost through evaporation or discharge is replaced; with the Centurio POOL the volume fed in is measured by a pulse-output water meter.
Typical layout
Typical layout
The treatment system is installed in the plant room, downstream of the filtration: the probes analyse a water sample and injection takes place on the delivery pipe to the pool.
Components
Basic components
Controller, pumps, probe holder and sample filter are supplied pre-assembled on a plastic panel; the probes are selected according to the parameters to be controlled.
Centurio POOL
Multi-channel controller with touch screen, the same as the Centurio PRO with software dedicated to swimming pools: it measures, controls, operates pumps and loads and logs the data.
Centurio controller →
Cells for free and total chlorine
Two closed (membrane) amperometric cells measure free chlorine and total chlorine; the controller calculates combined chlorine from the difference.
SCL cells →
pH and Redox electrodes
Combination electrodes for pH control and for indication of the Redox potential, which supplements the amperometric measurement.
pH electrodes →
Flow-through probe holder
With sample flow rate adjustment and flow sensor, which stops dosing when there is no circulation.
Probe holders →
Dosing pumps
External pumps for pH corrector and hypochlorite and, on request, for flocculant, algicide and dechlorinating agent, sized for the pool.
V and VMS pumps →
Pulse-output water meters
On the make-up and on the discharge: they measure the water volumes and control the dosing of the dechlorinating agent in proportion to the discharge.
Water meters →
Combined chlorine
How combined chlorine is measured
Combined chlorine, formed by chloramines, cannot be measured directly: the Centurio POOL derives it continuously from two amperometric measurements, as a subtraction.
Insight: chlorine and combined chlorine →
1
Total chlorine
A closed (membrane) amperometric cell, the SCL8, measures total chlorine: the sum of free chlorine and combined chlorine.
2
Minus free chlorine
A second cell, with a selective membrane, measures free chlorine, i.e. the fraction active in disinfection.
3
Equals combined chlorine
The controller subtracts free from total chlorine and displays and logs the combined chlorine, comparing it with the alarm thresholds; it must be kept within 0.4 mg/l.
Functions
Complete management of the swimming pool
Multi-parameter controller with touch screen for public and collective-use swimming pools: it measures and controls the water parameters, operates pumps and loads and continuously logs all the data.
Up to 10 measuring channels
Free chlorine, total chlorine and combined chlorine, pH and Redox, as well as chlorine dioxide, hydrogen peroxide, peracetic acid, turbidity, temperature, balance tank level, pump flow rate and filter pressure.
Free, total and combined chlorine
Two amperometric cells measure free chlorine and total chlorine; the controller calculates combined chlorine from the difference, an indicator of the presence of chloramines, to be kept within 0.4 mg/l. Redox supplements the amperometric measurement.
SCL cells →Dosing
Proportional dosing of pH corrector and disinfectant, shock chlorination, flocculant, algicide and dechlorination of the discharge; 8 alarm inputs.
6 timed outputs
Weekly or daily programming for lighting, filtration, algicide or any other load.
Transducers
Level, pressure and flow transducers for monitoring the chemical and balance tank levels, filter pressure and the hourly flow rate of the filtration pumps.
Proportional control
The pump runs at maximum frequency beyond the activation set point and reduces it progressively until it stops: for example pH from 8.00 to 7.00, free chlorine from 0.50 to 1.00 mg/l.
What it controls
What it can control
In addition to measurement and disinfection, the Centurio POOL supervises the plant serving the pool, with a single controller and a single remote control portal.
Filtration
It manages the scheduled start of the filtration pump and, by means of a transducer, monitors its hourly flow rate.
Filters
It detects the filter pressure and, by means of the turbidimeter on the water coming from the pool, signals when a backwash is required.
Turbidity →
Heating
The temperature probe improves the accuracy of the pH measurement and allows the water heating system to be controlled.
Lighting, cover, hydromassage
The 6 timed outputs control the lights, the pool cover, the hydromassage or other loads, according to weekly or daily programmes.
Make-up and discharge
Two pulse-output water meters measure the make-up and discharged volumes; on the discharge the controller doses the dechlorinating agent in proportion to the volume. It also monitors the balance tank level.
Water meters →
Disinfection and alarms
Free, total and combined chlorine, pH and Redox; shock chlorination, flocculant and algicide. Alarms for chlorine out of limits, probe failure, product level, no flow and out-of-range readings.
SCL cells →
Screens
Settings from the touch screen
Set points, programmes, water meters and graphs are managed directly from the controller or from the web portal.
Main page
pH set point
Chlorine set point
Weekly timers
Water meters
Graphs
Make-up
Measured make-up water
The daily make-up corresponds approximately to 5% of the pool volume. It is measured by the Centurio POOL, connected to a pulse-output water meter installed on the make-up pipe.
Centurio POOL
It logs the make-up volumes and, with a second water meter, the discharged volumes; it monitors the balance tank level and can dose a product in proportion to the measured volumes.
The water meter
Turbine or Woltmann water meters, for hot or cold water, with dry or wet dial, also available with PTFE-coated interior and exterior.
Water meters →
Dechlorination
Dechlorination of the discharge
Under the regulations in force, filter backwash water and drain-down water must be dechlorinated before discharge. With the pulse-output water meter on the discharge, the Centurio POOL doses the dechlorinating agent in proportion to the volume discharged.
Insight: swimming pool water discharges → Water meter on the discharge
The second water meter measures the volume discharged and controls the dechlorinating agent pump.
Water meters →
Dechlorinating agent pump
It doses the dechlorinating agent, for example sodium metabisulphite or hydrogen peroxide, into the discharge pipe.
Dechlorination systems →
Data sheet
Controller data sheet
Inputs, outputs, control modes and alarms of the controller.
Inputs
- 10 measuring channels
- Temperature
- Level, pressure and flow transducers
- 2 pulse-output water meters
- 8 alarm inputs
Outputs
- pH, chlorine, flocculant, algicide and dechlorinating agent pumps
- 6 timed outputs
Control
- Proportional
- Shock chlorination
- Proportional to the water meters
- Timed
Alarms
- Probe failure
- Chemical levels
- No flow
- Out-of-range reading
Communication
- Ethernet
- Wi-Fi
- Modbus RTU
- Modbus TCP/IP
- Current outputs
- 4G on request
Power supply
- 230 VAC
- 12 – 24 VDC
Technical data
Probe data sheet
pH electrodes
| Electrode | Pressure | Connection | Body | Minimum conductivity | Junction | Temperature | Cable | Diameter | Notes |
|---|---|---|---|---|---|---|---|---|---|
| EPHS | 7 bar (3.5 bar) | BNC | Epoxy | 100 µS | – | 70 °C (80 °C) | 0.8 m | 12 mm | – |
| EPHM | 7 bar (3.5 bar) | BNC | Epoxy | 100 µS | – | 70 °C (80 °C) | 4.5 m | 12 mm | – |
| EPHL | 7 bar (3.5 bar) | BNC | Epoxy | 100 µS | – | 70 °C (80 °C) | 15 m | 12 mm | – |
| EPHSN6 | 7 bar (3.5 bar) | SN6 with PG13.5 thread | Epoxy | 100 µS | – | 70 °C (80 °C) | 1 – 100 m | 12 mm | – |
| EPHMD/100 | 7 bar | BNC | Epoxy | 100 µS | Double | 100 °C | 4.5 m | 12 mm | – |
| EPHM/D | 7 bar (3.5 bar) | BNC | Epoxy | 100 µS | Double | 70 °C (80 °C) | 4.5 m | 12 mm | – |
| EPHM/D/SN6 | 7 bar (3.5 bar) | SN6 with PG13.5 thread | Epoxy | 100 µS | Double | 70 °C (80 °C) | 1 – 100 m | 12 mm | – |
| EPHMD/LI | 7 bar (3.5 bar) | SN6 with PG13.5 thread | Epoxy | 3 µS | Double | 70 °C (80 °C) | 1 – 100 m | 12 mm | For low-conductivity water |
| EPHSC | 7 bar (3.5 bar) | BNC | Epoxy | 100 µS | Double | 70 °C (80 °C) | 4.5 m | 12 mm | Self-cleaning |
| EPHSC/SN6 | 7 bar (3.5 bar) | SN6 with PG13.5 thread | Epoxy | 100 µS | Double | 70 °C (80 °C) | 1 – 100 m | 12 mm | Self-cleaning |
| EPHM/HF | 7 bar (3.5 bar) | BNC | Epoxy | 100 µS | Double | 70 °C (80 °C) | 4.5 m | 12 mm | Resistant to 1% hydrofluoric acid |
| EPHSN6 GK | 10 bar | SN6 | Glass | 150 µS | – | −5 / 135 °C | 1 – 100 m | 12 mm | High temperature |
All models: combination electrode, range 0 – 14 pH, resolution 0.01.
Redox electrodes
| Electrode | Range | Pressure | Connection | Body | Minimum conductivity | Junction | Temperature | Cable | Diameter | Notes |
|---|---|---|---|---|---|---|---|---|---|---|
| ERhS | ± 1,000 mV | 7 bar (3.5 bar) | BNC | Epoxy | 100 µS | – | 70 °C (80 °C) | 0.8 m | 12 mm | – |
| ERhM | ± 1,000 mV | 7 bar (3.5 bar) | BNC | Epoxy | 100 µS | – | 70 °C (80 °C) | 4.5 m | 12 mm | – |
| ERhL | ± 1,000 mV | 7 bar (3.5 bar) | BNC | Epoxy | 100 µS | – | 70 °C (80 °C) | 15 m | 12 mm | – |
| ERhHLB SN6 | ± 1,500 mV | 6 bar | SN6 with PG13.5 thread | Glass | 100 µS | – | 80 °C | 10 m | 12 mm | High linearity and sensitivity, for low chlorine concentrations |
| ERhSN6 | ± 1,000 mV | 7 bar | SN6 with PG13.5 thread | Epoxy | 100 µS | – | 100 °C | 1 – 100 m | 12 mm | – |
| ERhMD/100 | ± 1,000 mV | 7 bar | BNC | Epoxy | 100 µS | Double | 100 °C | 4.5 m | 12 mm | – |
| ERhM/D | ± 1,000 mV | 7 bar (3.5 bar) | BNC | Epoxy | 100 µS | Double | 70 °C (80 °C) | 4.5 m | 12 mm | – |
| ERhSC | ± 1,000 mV | 7 bar (3.5 bar) | BNC | Epoxy | 100 µS | Double | 70 °C (80 °C) | 4.5 m | 12 mm | Self-cleaning |
| ERhSC/SN6 | ± 1,000 mV | 7 bar (3.5 bar) | SN6 with PG13.5 thread | Epoxy | 100 µS | Double | 70 °C (80 °C) | 1 – 100 m | 12 mm | Self-cleaning |
All models: combination electrode, resolution 1 mV.
Closed (membrane) amperometric cells – Free chlorine
| SCL3N/0.5 | SCL3N/2 | SCL3N/20 | SCL18/0.5 | SCL18/2 | SCL18/20 | SCL3S/20 | |
|---|---|---|---|---|---|---|---|
| Measuring range | 0 – 0.5 mg/l | 0 – 2 mg/l | 0 – 20 mg/l | 0 – 0.5 mg/l | 0 – 2 mg/l | 0 – 20 mg/l | 0 – 20 mg/l |
| Resolution | 0.001 | 0.001 | 0.01 | 0.001 | 0.001 | 0.01 | 0.01 |
| Free chlorine | Inorganic | Inorganic | Inorganic | Inorganic | Inorganic | Inorganic | Organic and inorganic |
| Water | Fresh | Fresh | Fresh | Fresh | Fresh | Fresh | Fresh or salt |
| Electrodes | 2 | 2 | 2 | 3 | 3 | 3 | 2 |
| Selective membrane | Yes | Yes | Yes | No | No | No | Yes |
| Automatic compensation | pH and temperature | pH and temperature | pH and temperature | pH and temperature | pH and temperature | pH and temperature | Temperature |
| Self-cleaning | – | – | – | Yes | Yes | Yes | – |
| Operating pH | 5 – 9.5 | 5 – 9.5 | 5 – 9.5 | 5 – 9 | 5 – 9 | 5 – 9 | 5.5 – 9.5 |
| Operating temperature | 1 – 40 °C | 1 – 40 °C | 1 – 40 °C | 5 – 70 °C | 5 – 70 °C | 5 – 70 °C | 5 – 45 °C |
| Operating pressure | 1 bar | 1 bar | 1 bar | 8 bar | 8 bar | 8 bar | 1 bar |
| Water flow | 30 l/h | 30 l/h | 30 l/h | 40 l/h | 40 l/h | 40 l/h | 30 l/h |
Remote control
Remote control
Ethernet, Wi-Fi, Modbus RTU, Modbus TCP/IP and current outputs are standard; the 4G modem is available on request. From the web portal, free of charge and with no subscription, you can read the measurements, change set points, dosing and alarms and download the logged data.
Ethernet Standard
Connection to the web portal via network cable: measurements, set points, dosing and alarms accessible from PC, tablet and smartphone.
Wi-Fi Standard
Wireless connection to the web portal, with the same functions as the cable connection.
USB port Standard
Download of the logged data to a USB memory stick, for archiving and analysis with a spreadsheet.
Modbus RTU Standard
Integration into your PLC via serial port.
Modbus TCP/IP Standard
Integration into your PLC or SCADA via Ethernet network.
0-4/20 mA output Standard
Current signal proportional to the measured value, for remote monitoring or for controlling pumps and other instrumentation.
4G Optional
Connection via the cellular network for installations without a local network, with alarm notification by SMS or e-mail.
The NIMBUS portal
A single account brings together all registered installations, each with its own devices: the web portal, free of charge and with no subscription, can be accessed from PC, Mac, tablet and smartphone and allows every parameter to be both viewed and changed, with an encrypted connection and protected access.
Overview
On a single screen: probe readings, chemical levels, pump activation thresholds and active alarms, with the status of installations and devices (normal, warning, alarm, standby, not connected).
Installation map
Installations appear on an interactive map with their status and open with a click; for each one, the local weather conditions and temperature are also shown.
History and charts
Archive of measurements and alarms, available for consultation at any time with charts and numerical reports exportable in Excel format.
Alarms and notifications
Alarm thresholds for readings, dosing, faulty probe and out-of-range readings, with notification by e-mail or SMS depending on the communication system; a warning is also issued when an installation remains disconnected beyond the set time.
Set points and dosing
Remote modification of the set points, of the dosing pump activation thresholds and of the corresponding hourly flow rate.
Inputs and outputs
Status of relays, pulse outputs, digital inputs and current outputs, with the name assigned to each connection.
Maintenance calendar
Tasks are scheduled by installation or by device and assigned to technicians; a reminder is sent by e-mail two days before the due date. Each task is shown as scheduled, due, overdue or completed.
Team and permissions
The main account has full access and creates the technicians’ accounts, each enabled only for the assigned installations and devices; the last login and activity of each technician are visible.
Reports and activity log
Reports on devices, tasks and technicians, downloadable in PDF or CSV with the customer’s logo; the log keeps the history of operations and disconnections.
Customisation
Logo, main colour and light or dark theme; the tiles on the main screen can be rearranged by dragging them. Two installations can be displayed side by side for comparison.
Guided registration
Each device is added through a guided procedure: the model is recognised automatically and associated with the installation, together with the technician to be contacted.
PLC integration
As an alternative to the portal, the Modbus RTU or TCP/IP port allows integration into the plant supervision system.
Applications
Where it is used
For public and collective-use swimming pools and for high-end private facilities.
Public swimming pools and pools for collective use
Type 1, 2 and 3 pools according to UNI 10637:2024 (Italian standard): automatic measurement and control of pH and free chlorine.
Public swimming pools →
Private swimming pools
Residential pools, where free chlorine, Redox, hydrogen peroxide and salt are all options.
Private swimming pools →
Installation
Installation
Pre-assembled
All systems are supplied pre-assembled on a plastic panel, in a watertight box or on a skid, with solenoid or peristaltic dosing pumps.
In the plant room
Injection takes place on the delivery line, downstream of the filtration, by means of an injection valve or lance; the probes analyse a water sample in the flow-through probe holder.
Probe holders →Connection to the filtration
The controller must always remain powered, to maintain the polarisation of the electrodes; when the filtration pump stops it goes into stand-by, continuing to measure without dosing.
Installations
Installation examples
Systems are supplied pre-assembled and tested, in the form best suited to the plant room: on a panel, in a cabinet or on a skid (with cover, in a box or on a frame), also tailor-made. Some examples.
On a panel
Controller, pumps, probe holder and accessories mounted and wired on a wall panel.
In a cabinet
System panel and chemical tanks housed in a single cabinet.
Wall cabinet
Pipework, pumps and electrical panel in a wall cabinet with door.
Skid with cover
Skid with raised stainless steel frame and protective PMMA cover.
Skid in a box
Skid enclosed in a box with door, with the chemical tanks at the base.
Skid on a frame
Skid on a frame with doors, pre-assembled and ready for connection.
On the tank
Dosing pump mounted directly on the tank: the most compact solution.
In the plant room
Wall installation in the plant room, with the chemical tanks on the floor.
Pumps, controllers or components supplied by the customer can also be fitted, with custom dimensions, back panel and electrical panel. Dosing stations and skids →
Which one to choose
From the simplest to the most complete solution
For chlorine and other disinfectants the basic solution is the dosing station; to dose according to the concentration actually present in the water, measuring controllers are used.
Dosing station
The simplest solution: the pump doses at a constant rate or in proportion to the volume of water measured by the pulse-output water meter.
Details →
LDsRh
Dosing based on the Redox potential of the water: an economical solution, based on an indirect measurement.
Details →
LDsCL
The amperometric cell directly measures the disinfectant concentration in mg/l, ensuring maximum dosing accuracy.
Details →
LD Dual Parameter
Simultaneous management of two parameters, for example pH and chlorine, with a single controller.
Details → Centurio PRO
Management of up to 10 parameters and of all the pumps in the installation, with touch screen and remote control as standard.
Details →System design
Tell us the pool volume, the parameters to be controlled and the loads to be operated: we will propose probes, pumps and accessories and supply the system assembled on a panel.