Why is the dissolved oxygen probe so famous?
Dissolved oxygen refers to the free and non-compound oxygen present in water and other liquids. It is an important parameter in assessing water quality as it affects the living organisms within a water body. A dissolved oxygen level that is too high or too low can affect the living water bodies. Dissolved oxygen comes from two sources: from photosynthesis where it is a product and from the atmosphere. The dissolved oxygen probe will help deal with different circumstances in industrial spaces.
What is a Dissolved oxygen probe?
Dissolved oxygen probes are used to estimate the concentration of dissolved oxygen in water samples tested in the field or the laboratory. The dissolved oxygen probes are usually reported in parts per million (ppm) or milligrams per liter (mg/L).
The most popular method to measure dissolved oxygen is a measurement with a dissolved oxygen sensor or meter. The other measurement methods are optical and electrochemical sensors. Further, the electrochemical sensors are divided into polarographic, pulsed polarographic, and galvanic sensors. A meter is attached to the dissolved oxygen sensor.
Which is for spot sampling and laboratory applications or a data logger? It also works as a process monitor or transmitter for measurement and process control. Dissolved oxygen sensors are designed for biochemical oxygen demand tests ( BOD), spot sampling, or long-term monitoring applications.
How Do Dissolved Oxygen Probes Work?
The working system of Dissolved oxygen probes is not that complex. If you try to understand it step by step then there will be no problem. But if someone thinks that it’s so easy and will know by any hazardous way then he is completely wrong. So you have to understand it step by step, which is mentioned below. Read the complete content carefully and know about all the steps of how Dissolved oxygen probes work.
Here are all the steps: -
- Dissolved oxygen probes measure the amount of oxygen that diffuses across a permeable or semi-permeable membrane into a probe. A chemical reduction reaction occurs producing an electrical signal while the oxygen is inside the sensor. The DO probe reads the signal and the sensor displays it on the meter.
- To measure the DO in water, the titrimetric method is the most familiar one. Titration requires one liquid whose concentration is already determined ( titrant) to identify the concentration of the other. A dissolved oxygen probe works with the redox reaction process( oxidation-reduction) that provides continuous and live measurements.
- As they require an applied voltage, most DO probes need warm-up time before using them that polarizes the electrodes before measuring the DO in water. Once the DO probe is connected to the meter, the electrode is dipped into the solution that is to be tested. Through the process of diffusion, the oxygen molecule reaches the electrode through a permeable or semi-permeable membrane.
- A small amount of electrical current flows between the cathode and anode. The concentration of oxygen in the solution is directly proportional to the flow of current between the electrodes. Hence the amount of Do in the solution is measured by the measuring current flow through the calibrated meter. The two major types of the dissolved oxygen sensor are:
- Galvanic DO sensor: - It produces a voltage as the oxygen diffuses to the probe's membrane. Oxygen passes through the membrane and electrolytic solution to the electrodes. It dissolves inside the probe cap that contains the buffered electrolyte which allows O2 to react with the cathode (platinum electrode), from which it gains an electron. It is the electron that is given to the O2 molecule, creating a voltage between the anode (silver chloride electrode) and cathode inside the DO probe. Once current is detected by the DO probe it measures the DO concentration.
- Pro graphics DO sensor: - It also contains a thin semipermeable membrane. Voltage is given to the anode and cathode. The Oxygen molecule with an electron creates a current flow between the electrodes that measure the DO concentration in the solution.
Final words: -
Pick the dissolved oxygen sensor that fit your different needs and is also available at easy prices. The DO concentration is affected by temperature, salinity, atmospheric pressure, and humidity. So it is very important to check these parameters while measuring the dissolved oxygen concentration. Otherwise, you may have to face some serious problems.
