What is the principle of YSI dissolved oxygen meter detection?
YSI dissolved oxygen meter is specially designed for measuring ppb level dissolved oxygen in boiler feed water and condensate water. It ensures stability and accuracy at (ultra) low concentrations, and greatly improves measurement performance and usage environment. Dissolved oxygen meters are mainly used for continuous monitoring of dissolved oxygen values in solutions such as chemical fertilizers, metallurgy, environmental protection, pharmaceuticals, biochemistry, food and tap water.
The influence on the solubility of oxygen depends on the temperature, pressure and dissolved salts in the water. In addition, oxygen diffuses through the solution faster than through the membrane. If the flow rate is too slow, interference will occur.
The YSI dissolved oxygen meter has the characteristics of easy installation, long calibration cycle (3~4 months), insensitivity to other substances, etc., and can monitor the use of electrolytes in the coating and probe. Generally, the electrolyte and coating are replaced every one to three years. membrane.
The principle of the YSI dissolved oxygen meter is that when the fuel cell sensor is composed of a highly active oxygen electrode and a lead electrode, it is immersed in a KOH solution. At the cathode oxygen is reduced to hydroxide ions, while at the anode lead is oxidized. The KOH solution is separated from the outside world by a polymer film, and the sample gas does not directly enter the sensor. Therefore, the solution and lead electrode do not need to be cleaned or replaced regularly. Oxygen molecules in the sample gas diffuse into the oxygen electrode through the polymer film for electrochemical reaction. The current generated in the electrochemical reaction depends on the number of oxygen molecules that diffuse to the oxygen electrode, and the diffusion rate of oxygen is proportional to the number of oxygen molecules in the sample gas. Oxygen content, in this way, the output signal size of the sensor is only related to the oxygen content in the sample gas, and has nothing to do with the total amount of gas passing through the sensor. Through the connection of the external circuit, the charge transfer in the reaction, that is, the size of the current, is proportional to the oxygen participating in the reaction.
