Bleed-off
Opening of the drain valve when the conductivity set point is exceeded, with opening delay, dead band, maximum bleed-off time and manual control.
Complete controllers for cooling towers: they measure conductivity and control bleed-off, dose the antiscalant in proportion to the make-up water and manage two biocides with their activators. The two- and three-channel versions add pH, Redox or chlorine.
Opening of the drain valve when the conductivity set point is exceeded, with opening delay, dead band, maximum bleed-off time and manual control.
Dosing linked to bleed-off (Feed & Bleed, Feed & % Bleed), to a percentage of time (Feed & % Time) or to the make-up volume measured by the water meter, also at constant ppm.
Two biocides and two activators on a weekly programme, on a 4-week cycle, or daily; in the versions with Redox or chlorine the biocide can also be dosed according to the measurement.
Before the biocide and the activator, the controller drains water, for a set time or down to the set conductivity.
After the biocide has been dosed, bleed-off remains blocked for the set time, so that the chemical acts without being drained.
In the versions with pH, the controller also regulates the pH of the tower water.
All three models manage bleed-off, antiscalant and biocides; they differ in the parameters measured.
Conductivity, with conductive or inductive probe to be specified when ordering, and temperature. Bleed-off, antiscalant, two biocides and two activators.
Conductivity plus a second parameter of choice: pH (CD pH), Redox (CD Rh) or chlorine or another biocide (CD CL). On request, mA output and 12 or 24 VDC power supply.
CD pHConductivity and pH
CD RhConductivity and Redox
CD CLConductivity and chlorine
Three simultaneous parameters: conductivity, pH and chlorine (CD pH CL) or conductivity, pH and Redox (CD pH Rh), plus temperature. On request, mA output and 12 or 24 VDC power supply.
CD pH CLConductivity, pH and chlorine
CD pH RhConductivity, pH and Redox
| Function | MTOWER 1CH | MTOWER 2CH | MTOWER PLUS |
|---|---|---|---|
| Functions | |||
| Conductivity-based bleed-off | ● | ● | ● |
| Metered make-up and bleed-off | ● | ● | ● |
| Antiscalant proportional to make-up | ● | ● | ● |
| Two alternating biocides | ● | ● | ● |
| Pre-biocides (activators) | ● | ● | ● |
| Pre-bleed | ● | ● | ● |
| Drain lock-out | ● | ● | ● |
| pH control | – | ● | ● |
| Measurement-based biocide (Redox or chlorine) | – | ● | ● |
| Flow control | ● | ● | ● |
The probes are not included and are chosen according to the installation.
Conductivity, pH and chlorine on the same display, with the status of the dosing in progress and of the alarms.
Bleed-off set point, antiscalant mode, biocide and activator programmes, pre-bleed and lock-out are set from the controller or remotely from the web portal.
| MTOWER 1CH | MTOWER 2CH | MTOWER PLUS | |
|---|---|---|---|
| Parameters | Conductivity | Conductivity + pH, Redox or chlorine | Conductivity + pH + chlorine or Redox |
| Conductive conductivity | 0 – 300 µS … 0 – 300 mS | 0 – 300 µS … 0 – 300 mS | 0 – 300 µS … 0 – 300 mS |
| Inductive conductivity | 0 – 3, 30 or 300 mS | 0 – 3, 30 or 300 mS | 0 – 3, 30 or 300 mS |
| pH | – | 0 – 14 | 0 – 14 |
| Redox | – | ±999 mV | ±999 mV |
| Chlorine and other biocides | – | According to the cell | According to the cell |
| Inputs | 5 levels, 2 water meters, flow, temperature, stand-by | 6 levels, 2 water meters, flow, temperature, stand-by | 6 levels, 2 water meters, flow, temperature, stand-by |
| Proportional outputs | 2: inhibitor and biodispersant | 2 in the CD pH version: inhibitor and pH | 3: inhibitor, pH and chlorine or Redox |
| Biocides and activators | 2 + 2 | 2 + 2 | 2 + 2 |
| Temperature probes | 1 | 1 | 1 |
| On request | mA output; 12 or 24 VDC power supply | mA output; 12 or 24 VDC power supply | mA output; 12 or 24 VDC power supply |
| Alarms | Flow, 2 levels, bleed-off timeout | Flow, 2 levels, bleed-off timeout | Flow, 3 levels, bleed-off timeout |
Measurements are temperature-compensated. Optional communication, one chosen from USB, Ethernet, 4G, Wi-Fi and Modbus; 4/20 mA output optional. Probes are ordered separately.
PVDF body, graphite electrodes.
| Model | Mounting | Connection | Range | K factor | Temperature compensation |
|---|---|---|---|---|---|
| ECDC/1 | In-line / by-pass | R3/4" | 0 – 20 mS | 1 | – |
| ECDCC/1 | In-line / by-pass | R3/4" | 0 – 20 mS | 1 | NTC 10K |
| ECDCCPT/1 | In-line / by-pass | R3/4" | 0 – 20 mS | 1 | PT100 |
| ECDC/10 | In-line / by-pass | R3/4" | 0 – 200 mS | 10 | – |
| ECDCC/10 | In-line / by-pass | R3/4" | 0 – 200 mS | 10 | NTC 10K |
| ECDCCPT/10 | In-line / by-pass | R3/4" | 0 – 200 mS | 10 | PT100 |
| ECDCIM/1 | Immersion | G1/2" | 0 – 20 mS | 1 | – |
| ECDCCIM/1 | Immersion | G1/2" | 0 – 20 mS | 1 | NTC 10K |
| ECDCCIMPT/1 | Immersion | G1/2" | 0 – 20 mS | 1 | PT100 |
| ECDCIM/10 | Immersion | G1/2" | 0 – 200 mS | 10 | – |
| ECDCCIM/10 | Immersion | G1/2" | 0 – 200 mS | 10 | NTC 10K |
| ECDCCIMPT/10 | Immersion | G1/2" | 0 – 200 mS | 10 | PT100 |
Operating temperature 1 – 60 °C (100 °C at 2 bar), operating pressure 7 bar (2 bar at 100 °C).
PVDF body, stainless steel electrodes.
| Model | Mounting | Connection | Range | K factor | Temperature compensation |
|---|---|---|---|---|---|
| ECDI/1 | In-line / by-pass | R3/4" | 0 – 5 mS | 1 | – |
| ECDIC/1 | In-line / by-pass | R3/4" | 0 – 5 mS | 1 | NTC 10K |
| ECDICPT/1 | In-line / by-pass | R3/4" | 0 – 5 mS | 1 | PT100 |
| ECDI/01 | In-line / by-pass | R3/4" | 0 – 200 µS | 0.1 | – |
| ECDIC/01 | In-line / by-pass | R3/4" | 0 – 200 µS | 0.1 | NTC 10K |
| ECDICPT/01 | In-line / by-pass | R3/4" | 0 – 200 µS | 0.1 | PT100 |
| ECDIIM/1 | Immersion | G1/2" | 0 – 5 mS | 1 | – |
| ECDICIM/1 | Immersion | G1/2" | 0 – 5 mS | 1 | NTC 10K |
| ECDICPTIM/1 | Immersion | G1/2" | 0 – 5 mS | 1 | PT100 |
| ECDIIM/01 | Immersion | G1/2" | 0 – 200 µS | 0.1 | – |
| ECDIIM/02 | Immersion | G1/2" | 0 – 500 µS | 0.2 | – |
| ECDICIM/01 | Immersion | G1/2" | 0 – 200 µS | 0.1 | NTC 10K |
| ECDICPTIM/01 | Immersion | G1/2" | 0 – 200 µS | 0.1 | PT100 |
Operating temperature 1 – 60 °C (100 °C at 2 bar), operating pressure 7 bar (2 bar at 100 °C).
Epoxy body, platinum electrodes, diameter 12 mm.
| Model | Mounting | Range | K factor | Temperature compensation |
|---|---|---|---|---|
| ECDHL/1 | In-line / by-pass | 0.2 – 20 mS | 1 | – |
| ECDHLC/1 | In-line / by-pass | 0.2 – 20 mS | 1 | NTC 10K |
| ECDHLCPT/1 | In-line / by-pass | 0.2 – 20 mS | 1 | PT100 |
| ECDHL/01 | In-line / by-pass | 0 – 200 µS | 0.1 | – |
| ECDHLC/01 | In-line / by-pass | 0 – 200 µS | 0.1 | NTC 10K |
| ECDHLCPT/01 | In-line / by-pass | 0 – 200 µS | 0.1 | PT100 |
| ECDHL/10 | In-line / by-pass | 20 – 200 mS | 10 | – |
| ECDHLC/10 | In-line / by-pass | 20 – 200 mS | 10 | NTC 10K |
| ECDHLCPT/10 | In-line / by-pass | 20 – 200 mS | 10 | PT100 |
Operating temperature 1 – 70 °C, operating pressure 7 bar.
Stainless steel body and electrodes, R3/4" connection, in-line or by-pass mounting.
| Model | Range | K factor | Temperature compensation | Operating temperature |
|---|---|---|---|---|
| EICDC/1 | 0 – 20 mS | 1 | NTC 10K | 1 – 130 °C |
| EICDCPT/1 | 0 – 20 mS | 1 | PT100 | 1 – 130 °C |
| EICDC/01 | 0 – 200 µS | 0.1 | NTC 10K | 1 – 130 °C |
| EICDCPT/01 | 0 – 200 µS | 0.1 | PT100 | 1 – 130 °C |
| EICDC/001 | 0 – 20 µS | 0.01 | NTC 10K | 1 – 130 °C |
| EICDCPT/001 | 0 – 20 µS | 0.01 | PT100 | 1 – 130 °C |
| EICDCHPT/1 | 0 – 20 mS | 1 | PT100 | 1 – 200 °C |
| EICDCHPT/01 | 0 – 200 µS | 0.1 | PT100 | 1 – 200 °C |
| EICDCHPT/001 | 0 – 20 µS | 0.01 | PT100 | 1 – 200 °C |
Operating pressure 15 bar.
| ECDINDPT | ECDSINDPT | |
|---|---|---|
| Measuring range | 0.3 – 3 mS 0.3 – 30 mS 0.3 – 300 mS | 0.3 – 10 mS |
| Measuring system | Inductive | Inductive |
| Body | PEEK | PEEK |
| Mounting | In-line / by-pass / immersion | In-line / by-pass / immersion |
| Temperature compensation | PT100 | PT100 |
| Operating temperature | 1 – 85 °C (100 °C for temporary measurement) | 1 – 85 °C (100 °C for temporary measurement) |
| Operating pressure | 8 bar | 8 bar |
| 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.
| 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.
| 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 |
| SCL2/0.5 | SCL2/2 | SCL2/20 | SCL17/0.5 | SCL17/2 | SCL17/20 | |
|---|---|---|---|---|---|---|
| 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 |
| Resolution | 0.001 | 0.001 | 0.01 | 0.001 | 0.001 | 0.01 |
| Electrodes | 2 | 2 | 2 | 3 | 3 | 3 |
| Selective membrane | Yes | Yes | Yes | No | No | No |
| Self-cleaning | – | – | – | Yes | Yes | Yes |
| Operating pH | 1 – 6 | 1 – 6 | 1 – 6 | 5 – 9 | 5 – 9 | 5 – 9 |
| Operating temperature | 1 – 40 °C | 1 – 40 °C | 1 – 40 °C | 5 – 70 °C | 5 – 70 °C | 5 – 70 °C |
| Operating pressure | 1 bar | 1 bar | 1 bar | 8 bar | 8 bar | 8 bar |
| Water flow | 30 l/h | 30 l/h | 30 l/h | 40 l/h | 40 l/h | 40 l/h |
Automatic temperature compensation on all models.
| SCL8/2 | SCL8/20 | SBR/20 | SCL9 | SCL11/200 | SCL11/2000 | SCL10 | SCT | |
|---|---|---|---|---|---|---|---|---|
| Measurement | Total chlorine | Total chlorine | Bromine | Hydrogen peroxide | Peracetic acid | Peracetic acid | Ozone | Chlorites |
| Measuring range | 0 – 2 mg/l | 0 – 20 mg/l | 0 – 20 mg/l | 0 – 200 mg/l | 0 – 200 mg/l | 0 – 2,000 mg/l | 0 – 20 mg/l | 0 – 2 mg/l |
| Resolution | 0.001 | 0.01 | 0.01 | 0.1 | 0.1 | 1 | 0.01 | 0.001 |
| Operating pH | 4 – 12 | 4 – 12 | 6.5 – 9.5 | 1 – 11 | 1 – 6 | 1 – 6 | 2 – 11 | 5.5 – 9.5 |
| Operating pressure | 1 bar | 1 bar | 0.5 bar | 1 bar | 1 bar | 1 bar | 1 bar | 1 bar |
All models: 2 electrodes, selective membrane, automatic temperature compensation, operating temperature 1 – 40 °C, water flow 30 l/h.
The controllers can be remotely controlled bidirectionally (read and write) from the web portal, from PC, tablet and smartphone: viewing of measurements, modification of set points, dosing and alarms, receipt of alarms and download of logs. Alternatively, integration into your PLC via Modbus is possible.

Connection via the cellular network for installations without a local network, with alarm notification by SMS or e-mail.
Connection to the web portal via network cable: measurements, set points, dosing and alarms accessible from PC, tablet and smartphone.
Download of the logged data to a USB memory stick, for archiving and analysis with a spreadsheet.
Wireless connection to the web portal, with the same functions as the cable connection.
Integration into your PLC via serial port.
Current signal proportional to the measured value, for remote monitoring or for controlling pumps and other instrumentation.
Optional communication: one only, chosen from 4G, Ethernet, USB, Wi-Fi and Modbus. The 4/20 mA output is available as an option with all communication types.
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.
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).
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.
Archive of measurements and alarms, available for consultation at any time with charts and numerical reports exportable in Excel format.
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.
Remote modification of the set points, of the dosing pump activation thresholds and of the corresponding hourly flow rate.
Status of relays, pulse outputs, digital inputs and current outputs, with the name assigned to each connection.
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.
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 on devices, tasks and technicians, downloadable in PDF or CSV with the customer’s logo; the log keeps the history of operations and disconnections.
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.
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.
As an alternative to the portal, the Modbus RTU or TCP/IP port allows integration into the plant supervision system.
The controller is also supplied pre-assembled on a panel, with the probe holder, the bleed-off valve, the dosing pumps and the make-up and bleed-off water meters.
Controller, dosing pumps, probe holder and motorised bleed-off valve pre-assembled.
The system →
Panel with MTOWER, probe holder and bleed-off valve for managing drainage, measurement and dosing.
Panels for cooling towers →
Risks, circuit, typical layout and treatment programming of cooling towers.
Systems for cooling towers →When the conductivity set point is reached, the controller opens the drain valve, with opening delay, dead band and safety timer (timeout): beyond the set time the drain closes and the alarm is triggered.
Inputs for pulse-output water meters: counting of make-up and drain volumes and control of the cycles of concentration.
The antiscalant is dosed in proportion to the make-up water (via a water meter or at constant ppm), together with the bleed-off or for a percentage of its duration.
Management of two different biocides with daily or weekly scheduling, alternated to prevent microorganisms from adapting to a single product.
Two outputs dedicated to pre-biocides, dosed for the set time before the biocide: they generally act as activators of the subsequent dosing.
Before biocide dosing the controller opens the drain, on a timed basis or down to a lower conductivity value; with conductivity-based pre-bleed, the bleed-off timeout applies.
After biocide dosing the drain remains inhibited for the set time, so as to ensure the necessary contact time and prevent loss of chemical through the drain.
pH measurement and dosing of acid or base, for pH-controlled towers.
Models: MTOWER 2CH, MTOWER PLUS
The oxidising biocide is dosed according to the Redox potential or the concentration in mg/l measured by an amperometric cell (chlorine, bromine, chlorine dioxide…).
Models: MTOWER 2CH, MTOWER PLUS
In the absence of flow in the probe holder (circulation pump stopped), dosing is suspended and the alarm is triggered.
Tell us the characteristics of the tower and the chemicals used: we will propose the most suitable model, probes and panel.
Call or write to us: a technician will reply with a tailored proposal of controllers, pumps, probes and accessories.