China Wholesale Optical RS485 Online Dissolved Oxygen Sensor Dissolved Oxygen Sensor Instrument Measurement Manufacturer

China Wholesale Optical RS485 Online Dissolved Oxygen Sensor Dissolved Oxygen Sensor Instrument Measurement Manufacturer PFDO-700

Dissolved oxygen sensor PFDO-700

Dissolved oxygen is a parameter that characterizes the concentration of oxygen in aqueous solution. It is free oxygen dissolved in water. The amount of dissolved oxygen in water is an indicator of the self-purification ability of water. High dissolved oxygen is conducive to the degradation of various pollutants in water, so that the water can be purified faster; conversely, low dissolved oxygen means that pollutants in water are degraded more slowly. Measuring the content of dissolved oxygen is one of the important indicators in water quality and environmental monitoring.

1. Classification of dissolved oxygen sensors

Currently, there are two main types of dissolved oxygen sensors available on the market, based on the measurement principle: polarography and fluorescence.

Polarographic dissolved oxygen sensor (also known as membrane method, constant voltage method)

Polarographic dissolved oxygen sensor works on the electrochemical principle. It consists of a working electrode (cathode), a counter electrode (anode), a reference electrode, a voltage source and a current detector. The cathode is immersed in the electrolyte solution, and the anode is separated from the sample by a gas-permeable membrane. When voltage is applied, oxygen diffuses through the membrane and is reduced at the cathode, generating a current proportional to the oxygen concentration, which is converted into dissolved oxygen concentration.

Fluorescence dissolved oxygen sensor

The fluorescence dissolved oxygen sensor has a built-in light source. The sensor emits blue light to illuminate the fluorescent material on the fluorescent cap. The fluorescent material is excited to emit red light. Since oxygen molecules can take away energy (quenching effect), the time and intensity of the excited red light are inversely proportional to the concentration of oxygen molecules. The concentration of dissolved oxygen in the water can be calculated.

Advantages of fluorescence method

●No membrane, no electrolyte, no polarization required, no oxygen consumption, not affected by flow rate;

●Not interfered by chemical substances such as carbon dioxide and sulfide;

●Small annual drift, fast response, more accurate measurement;

●Strong anti-interference ability, good stability, online measurement capability in complex situations, no reagent pollution.

2. Overview of Probest dissolved oxygen products (with Utility Model Patent Certificate)

Probest dissolved oxygen sensor adopts advanced fluorescence measurement technology, which is not affected by interference factors such as chloride ions and metal ions in water, has strong anti-interference ability and high stability; it does not need to replace the diaphragm and electrolyte, reduces maintenance workload and improves work reliability; and it has an automatic temperature compensation function inside, which can reduce measurement errors and increase measurement accuracy.

3. Product Features

1). Real-time monitoring

It can monitor the dissolved oxygen content in the water in real time, providing timely and accurate data support for water quality monitoring; it can measure continuously for 24 hours.

2). High precision

Precise resolution and measurement accuracy; built-in self-diagnosis function to ensure data accuracy; built-in NTC temperature compensation function to ensure good repeatability and stability of measurement results.

3). Anti-interference

Not affected by substances such as carbon dioxide, sulfate, chloride ions, and no flow rate/agitation requirements.

4). Easy maintenance

No diaphragm and electrolyte, basically no maintenance required, long service life.

5). Wide voltage power supply design

The sensor's wide power supply design of 9~36VDC is compatible with the application scenario requirements of 12VDC and 24VDC.

6). Open and flexible communication protocol:

Adopting MODBUS communication protocol, it is highly flexible and can be easily connected to a computer for monitoring and communication.

7). High protection level

Waterproof level IP68, according to the corrosion resistance requirements of different scenarios, the shell can be made of 316L stainless steel or titanium alloy, which can resist salt and alkali corrosion for a long time and ensure stability.

4. Typical applications

Municipal and industrial wastewater treatment: including regulating tanks, aeration tanks, aerobic tanks, anaerobic tanks and effluents, etc. Online monitoring of dissolved oxygen

Online monitoring of dissolved oxygen in water environments such as rivers, lakes, seawater, and fisheries

6. Technical parameters