Online dissolved oxygen analyzerIt is an intelligent analysis device for online analysis of dissolved oxygen in water quality, consisting of a dissolved oxygen transmitter (controller) and a dissolved oxygen sensor (electrode), which can monitor the oxygen content in water in real time and implement data transmission and storage functions.
Online dissolved oxygen analyzerThe polarographic film method is commonly used as the measurement principle:
The solubility of oxygen in water depends on temperature, pressure, and the salts dissolved in the water. The sensing part is composed of a gold electrode (cathode) and a silver electrode (anode), as well as KCL or potassium hydroxide electrolyte. Oxygen diffuses into the electrolyte through the membrane and forms a measurement circuit with the gold and silver electrodes. When a polarization voltage of 0.6~0.8V is applied to the dissolved oxygen electrode, oxygen diffuses through the membrane, the cathode releases electrons, the anode accepts electrons, and a current is generated. According to Faraday's law, the current flowing through a dissolved oxygen electrode is proportional to the oxygen partial pressure, and there is a linear relationship between the current and oxygen concentration at a constant temperature.
Features of online dissolved oxygen analyzer:Built in compensation: Equipped with automatic temperature/salinity compensation, effectively eliminating environmental interference.
Convenient maintenance: Adopting replaceable membrane and electrolyte structure, with long maintenance cycle and low cost.
Fast response: Fast response time (T90<60 seconds), no need for sample pretreatment, suitable for continuous online monitoring.
Flexible output: With two sets of relay outputs, it can independently and freely choose high and low position control; Isolated 4-20mA current output, communication interface can choose RS-485 for easy access to automation control system.
Easy to operate: The program design is simple, the operating interface is clear, ensuring that users can directly get started with the operation.
Attention: The polarographic film method belongs to the oxygen consuming type. When there are pollutants on the film, it can cause measurement errors. It needs to be cleaned regularly and care should be taken not to damage the film; Regularly replace the internal electrolyte, replace the membrane, and clean the silver electrode for dissolved oxygen electrodes; If electrode leakage is found, the electrolyte must be replaced.