Top 7 water quality sensors for water treatments easily

water quality sensors

Water is the source of life, and human beings cannot do without water in life and production activities. The quality of drinking water is closely related to human health. Water quality monitoring and governance have become an important topic of modern science. The water quality online monitoring system can accurately, timely, and comprehensively reflect the current water quality and development trend, and provide a scientific basis for water treatment projects. The sensing front end of the water quality monitoring system is a water quality sensor.

The water quality sensor measures water parameters such as conductivity, dissolved oxygen, pH, COD, residual chlorine, and turbidity through a variety of methods such as water chemical, physical and biological reactions, and provides data support for researchers, observers, and engineers. It is used in laboratory research, environmental management improvement, marine water quality assessment, hydraulic model calibration, sewage treatment, and other fields.

What is a water quality sensor?

The water quality sensor is a general term for multiple sensors that measure PH, residual chlorine, turbidity, suspended solids, COD, BOD, conductivity, and dissolved oxygen. Water quality does not refer to a specific day parameter, it contains multiple elements to measure water conditions.

Types of water quality sensors

Water quality is a general concept, and it covers a wide range. Therefore, building a complete water quality monitoring system is a complicated project. The good news is that with these seven Renke water quality sensors and a water quality monitoring host, you can easily build your water quality monitoring system.

  • PH Sensor
  • Conductivity Sensor
  • Residual Chlorine Sensor
  • Turbidity Sensor
  • ORP Sensor
  • COD Sensor
  • Ammonia Nitrogen Ion Sensor

The PH value is an important indicator for monitoring industrial wastewater. In industrial wastewater, most microorganisms have an adaptation range of pH 4.5-9, and the most suitable pH range is 6.5-7.5. When the pH is lower than 6.5, the fungus starts to compete with the bacteria. When the pH reaches 4.5, the fungus will have a complete advantage in the biochemical tank, which will seriously affect the settlement of the sludge. When the pH exceeds 9, the metabolic rate of microorganisms will be hindered.

In order to monitor the PH value of industrial wastewater, we generally use PH sensors. The PH sensor is a sensor used to monitor the concentration of hydrogen ions in the tested solution and convert it into a corresponding usable output signal. It is suitable for industrial sewage, domestic sewage, agriculture, aquaculture, and other scenarios in a non-corrosive weak acid and weak alkali environment.

Conductivity refers to the ability to conduct current in a body of water. In water quality monitoring, conductivity is one of the important indicators reflecting water quality. When the conductivity value of the water is higher, the conductivity is better, and the TDS value in the water is larger. The TDS value represents the content of dissolved impurities in the water. The larger the TDS value, the greater the impurity content in the water. On the contrary, the smaller the impurity content, the greater the water. Pure, the lower the conductivity.

Conductivity sensors can be divided into electrode-type conductivity sensors, inductive conductivity sensors, and ultrasonic conductivity sensors according to different measurement principles. Electrode type conductivity sensor adopts resistance measurement method according to electrolytic conduction principle. The inductive conductivity sensor realizes the measurement of liquid conductivity based on the principle of electromagnetic induction. Ultrasonic conductivity sensors measure conductivity according to the changes of ultrasonic waves in liquids, and the first two sensors are widely used.

RS-EC-*-2 EC sensor adopts electrode type conductivity measurement method, the built-in high-precision sensor is accurate, its conductivity measurement range is between 0~20000μS/cm, measurement error is ±1%FS, high sensitivity. This conductivity sensor comes with a cable connected to the transmitter, which sends the signal to the processing and/or recording equipment.

Residual Chlorine Sensor

Residual chlorine refers to the general term for free chlorine and combined chlorine remaining in the water after chlorinated disinfection and contact for a certain period of time.

Residual chlorine sensor KH-CL-N01-1 is used to measure residual chlorine, chlorine dioxide and ozone in water. The electrode structure is simple, easy to clean and replace. It can be used in drinking water treatment plants, canning plants, drinking water distribution networks, swimming pools, cooling circulating water, water quality treatment projects, and other occasions where continuous monitoring of the residual chlorine content in the aqueous solution is required.

Turbidity Sensor

Turbidity is caused by suspended particles in the water. The suspended particles diffusely reflect the incident light. Usually, the scattered light in the direction of 90 degrees is used as the test signal. The scattered light and turbidity conform to a multi-segment linear relationship, so the sensor needs to be calibrated at multiple points.

The KH-ZD-N01-1 turbidity sensor is designed and manufactured using the principle of scattered light turbidity measurement. Accurately measure the amount of light passing through the water to accurately measure the suspended solids in the water, and these suspended solids can reflect the pollution of the water body. In this way, the turbidity in the water sample is measured, and the final value is output after linearization processing. It is often used in the accurate measurement of rivers, sewage, and wastewater by water quality detectors.

ORP Sensor

The oxidation-reduction potential (ORP) is an important indicator to measure the water quality of aquaculture waters, and the ORP value can reflect the quality of the water. The oxidation-reduction potential reflects the oxidation-reduction state of the water body. The larger the ORP value, the stronger the oxidizing property of the water body, and the smaller the value, the stronger the reducing property of the water body.

The ORP sensor is mainly used as the oxygen reduction potential of the solution. It can not only detect the water body, but also detect the ORP data in the soil and culture medium. Therefore, it is also a sensor with many applications and can be widely used in electric power and chemical engineering. Continuous monitoring of ORP of various water quality in industries such as environmental protection, medicine, and food. Usually, it will be used with PH sensor.

COD Sensor

Many organic substances dissolved in water absorb ultraviolet light. Therefore, by measuring the degree of absorption of 254nm wavelength ultraviolet light by these organic substances, the content of dissolved organic pollutants in water can be accurately measured.

The KH-COD-N01-1 COD sensor uses two light sources, one ultraviolet light is used to measure the COD content in the water, the other reference light is used to measure the turbidity of the water body, and the light path attenuation is compensated by a specific algorithm and can be used to a certain extent. Eliminate the interference of particulate suspended matter impurities, so as to achieve more stable and reliable measurement.

Ammonia Nitrogen Ion Sensor

In aquaculture, if the ammonia nitrogen in the water is too high, it will poison fish and shrimp and cause fish and shrimp death. Therefore, the water quality ammonia hydrogen sensor is particularly necessary to monitor the ammonia nitrogen concentration. The ammonia nitrogen sensor is used to measure the ammonia nitrogen content of water quality, and is often used in the Internet of Things, aquaculture, intelligent agriculture and other fields.

The KH-NHN-N01-1 ammonia nitrogen sensor is made of ammonium ion selective electrode based on PVC membrane. It is used to test the ammonium ion content in water with temperature compensation to ensure that the test is fast, simple, accurate and economical. This user manual introduces the technical parameters, maintenance and communication protocol of the ammonia nitrogen sensor in detail.


Water quality monitoring covers a wide range of areas, and different application sites need to monitor different parameters. For specific selection and operation, please contact us. We have professional technicians to provide you with the best matching plan.