Municipal Drinking Water


Water Treatment

Halogen Systems has found a better way to monitor chlorine in drinking water:

We now have a new 5 parameter sensor with 3 electrode amperometric chlorine measurement. It does not require the use or reagents, membranes, or electrolyte.  It is self-cleaning and flow independent.  It is NSF61 Certified and can be installed directly in a pipe. Halogen’s sensor is unlike any other sensor on the market today.  It accurate and low maintenance.  pH compensation is included and automatic.

This versatile sensor can be installed in a flow cell, directly in a pipe, or even immersed direct in a tank or channel. Simple installation and low cost of operation.


  • Free or Total Chlorine
  • pH
  • Conductivity
  • Temperature
  • ORP


  • Easy Install
  • Installed directly in wet tap valve, side stream or immersion.
  • Submersible Immersion mounting options
  • Sensor may one hundred feet or more from monitor or SCADA input
  • Display connects to up 5 sensors
  • Connects directly into a SCADA (Supervisory Control and Data Acquisition) system suing Modbus RTU.
  • 24VDC or 90 to 240 VAC operation

Halogen Systems TRO Sensor Unique Features Include:

  • Low maintenance – the sensor is self-cleaning.
  • No reagents
  • Flow independent – not affected by pressure fluctuations or flow changes.
  • No membranes or electrolyte
  • No waste stream required.
  • Low drift- calibration stable for many months
  • Factory calibrated.

Reduced Cost of Ownership


Direct Pipe Insertion Amperometric

Old Technology Amperometric

Not Affected by Flow



Direct insertion



No Membranes



No Waste stream






High Pressure pH Sensor



Includes pH Compensation



Calibration or service (months)

6 to 12



Halogen Sensor


Reagent cost***



Water cost*  **



Wear Parts






Halogen Savings Annually



* $900 acre/foot water cost (MWD 2018)
**500 mL DPD water Flow Rate (69,204 gallons per year)
***Reagent cost $61.29 per package


Halogen Systems Chlorine Sensor


Flow Independent Measurement

Our Chlorine sensor is unaffected by flow velocity changes from 0 to 12 f/s. (HSI 06, 2020). This sensor style has an integrated pump, which uses a long-life brushless motor to deliver a fixed velocity across the electrodes, creating flow independence. The high velocity flow across the electrodes also improves sensitivity and improves the Signal to Noise Ratio.

No Waste Stream

Ease Of Service

A Wet Tap installation method enables direct insertion into a distribution pipe. The highly integrated design reduces the electronics cost and size, while increasing reliability.

Self-Cleaning Amperometric Chlorine Sensor

An electrochemical cleaning method resists polarization and adsorption of organics.  Cleaning beads continuously clean the sensor. This keeps the electrode surfaces, including the pH sensor, free from buildup of hardness and biofouling. Solid metal electrodes last the life of the system.

These features combine to enable long intervals between calibration. In freshwater tests, calibrations were stable for more than 3 months.

The Details

Better Information & Additional Parameters

This multiparameter sensor measures four other parameters in a single compact package. These measurements provide the utility with information far beyond the free chlorine level. There is no need for recalibration under changing water conditions.

Discrete sensor systems with a similar number of parameters often cost five or six times as much.


All these parameters mentioned below are transmitted via the Modbus communication protocol. An optional local Display is available for viewing parameters, troubleshooting and calibration

Amperometric Free or Total Chlorine

Free chlorine is measured every 45 seconds. The readings are pH, temperature and conductivity compensated.

Integrated pH Sensor

Two-year life versus the industry average of six months. This sensor cartridge is an integral part of the sensor and continually cleaned. This unique pH sensor can tolerate pressures up to 200 PSI. The pH sensor does not need frequent calibration.

Oxidation Reduction Potential (ORP)

Measuring ORP in drinking water provides another indicator of possible contamination or piping failure. This unique method of measuring ORP keeps the electrodes clean.

Integrated Conductivity Sensor

Changes in conductivity are important to water utilities and can indicate contamination, a pollution event, or other problems.

Types of Install

MUNICIPAL Water Chlorine Sensor Application

Side Stream

The side stream version of the sensor can be installed for either temporary or permanent monitoring of water treatment branches.  The sensor requires only a small flow of 0 to 0.5 GPH for operation. 

In Tank Installation

Since the sensor does not require any flow, it can be installed in a tank.

Immersion Installation

Open channel installation with a boom.

Click below to visit our other site to learn more about our Municipal Water Treatment & Wastewater analyzers

Power Options

Several power options are available.

  • 120V AC
  • 24 VDC power from a SCADA system
  • Remote power, battery, and solar panel