Analysis of the working principle of water quality detector-dissolved oxygen
There are two main technologies for measuring dissolved oxygen: optical-based methods, commonly known as luminescence, and chemical and electrical Clarke electrodes or membrane electrode assemblies. Slight changes are found on the inside of the two technologies. For example, there are two types of optical sensors. These two types of optical sensors measure the luminescence affected by the presence of oxygen, the measured length of the luminescence and the intensity of the luminescence. Therefore, we will introduce some electrode working methods of the dissolved oxygen water quality detector. I hope you can make better use of it after understanding it.
How Dissolved Oxygen Electrodes Work
Dissolved Oxygen Electrode Connector
The dissolved oxygen electrode of the water quality detector generally works according to the principle of photoluminescence extinction. The gas permeable layer phosphor is excited by short blue illumination. Dissolved oxygen present in the water comes into contact with the excited phosphor layer resulting in the emission of red photons. The emission frequency and duration of red light are measured against the red light signal to determine the concentration of dissolved oxygen in the water. The signal from the transmitter is a digital signal. The signal value is compensated for temperature and conductivity in the sensor.
The optical measurement duration or luminescence intensity method of the water quality detector detects dissolved oxygen based on the luminescence and extinction duration and intensity associated with carefully selected dyes. When no oxygen is present, the duration of the signal intensity is at its peak. When oxygen is introduced into the sensing element, the duration of the luminous intensity decreases. Thus, the duration and intensity of the glow is inversely proportional to the amount of oxygen present. Since oxygen pressure decreases with altitude, the solubility of oxygen decreases with altitude (that is, as atmospheric pressure decreases).
