Free Chlorine (Cl₂) refers to the portion of chlorine available in water as an effective disinfectant, typically present as hypochlorous acid (HOCl) and hypochlorite ion (OCl⁻). It is the most commonly used parameter for monitoring disinfection in drinking water, swimming pools, and industrial water systems.
Free chlorine is responsible for killing bacteria, viruses, and other microorganisms. It is fast-acting and effective, but its efficiency is strongly influenced by the pH value of the water—lower pH levels increase the proportion of hypochlorous acid, which is more effective than hypochlorite.
JUMO free chlorine sensors are used in numerous applications, such as:
- Drinking water treatment: Ensuring safe levels of disinfection and compliance with legal limits for residual chlorine.
- Swimming pools and spas: Continuous monitoring to maintain hygiene and user safety.
- Industrial water systems: Monitoring disinfection in cooling and process water systems.
- Food and beverage industry: Verification of disinfection processes during CIP cleaning and water usage.
- Pharmaceutical industry: Control of purified water systems to prevent microbial growth.
Free chlorine is also widely used in:
- Municipal water networks: Monitoring chlorine residuals throughout the distribution system.
- Cooling towers: Preventing microbial contamination and biofilm formation.
- Agriculture and horticulture: Disinfecting irrigation systems and ensuring water safety for plants and livestock.
- Surface disinfection: Used in various sectors to sanitize equipment, containers, and surfaces.
- Emergency water treatment: Quick and reliable disinfection during natural disasters or in remote areas.
These amperometric sensors with membrane are used to determine the concentration of free chlorine. They are able to measure various inorganic chlorine compounds, including chlorine gas (Cl₂), electrolytically generated chlorine, sodium hypochlorite (NaOCl), calcium hypochlorite (Ca(OCl)₂) and chlorinated lime (Ca(OCl)Cl). Testing for the complete absence of free chlorine is not possible with these sensors. Depending on the version, the sensors either supply a temperature-compensated current signal (4-20 mA) in an analogue version or a Modbus RTU signal via a digital interface. Calibration takes place in a downstream device such as an indicator, controller, recorder or programmable logic controller (PLC). The sensors can be connected directly to various transmitters or controllers. These supply the system with the required voltage and enable uncomplicated calibration. Areas of application: The sensors are used to measure free chlorine in drinking water, bathing water, industrial water, process water and cooling water. Frequently Asked Questions Was macht dieses Produkt so besonders? It measures the chlorine level in the water to monitor water quality. Wo wird das Produkt eingesetzt? It is suitable for monitoring free chlorine in water, for example in swimming pools or drinking water systems. Kann ich das Produkt dauerhaft nutzen? Yes. The sensor takes continuous measurements and is suitable for continuous operation. Ist der Sensor für Schwimmbäder geeignet? Yes. It is specifically designed for monitoring chlorine in swimming pool water. Wie wird der Messwert ausgegeben? Depending on the version, as a 4–20 mA signal or digitally via Modbus RTU. Muss ich den Sensor direkt am Gerät kalibrieren? No. Calibration is performed via external devices such as controllers or control systems. In welche Systeme lässt sich der Sensor integrieren? It can be easily integrated into existing measurement and control systems. Für welche Wasserarten ist der Sensor geeignet? For drinking water, process water, cooling water, and other applications involving chlorinated water.