Oxygen Analyzer Fuel Cell Electrochemical Method

The oxygen analyzer uses a completely sealed fuel cell oxygen sensor is one of the most advanced oxygen measurement methods in the world. The fuel cell oxygen sensor is composed of a highly active oxygen electrode and a lead electrode, and is immersed in the KOH solution. Oxygen is reduced to hydroxide ions at the cathode, and lead is oxidized at the anode.

The solution is separated from the outside by a layer of polymer film, the sample gas does not directly enter the sensor, so the solution and the lead electrode do not need to be cleaned or replaced regularly. The oxygen molecules in the sample gas diffuse through the polymer film to the oxygen electrode for electrochemical reaction. The current generated in the electrochemical reaction depends on the number of oxygen molecules diffused into the oxygen electrode, and the diffusion rate of oxygen is proportional to 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 not to the total amount of gas passing through the sensor. The oxygen analyzer is connected by an external circuit, and the charge transfer in the reaction, that is, the magnitude of the current is proportional to the oxygen participating in the reaction. Using this method for oxygen measurement, it is not affected by the reducing gas in the measured gas, eliminating many sample gas processing systems. It is faster than the old-fashioned “gold-net-lead” primary battery to measure oxygen and does not require a long blow-out process. The “gold-net-lead” primary battery sample gas directly enters the solution, resulting in a large amount of instrument maintenance and fuel The sample gas of the battery method does not directly enter the solution, and the sensor can work very stably and reliably for a long time. In fact, fuel cell oxygen sensors are completely maintenance-free. However, during use, frequent calibration is required to ensure the accuracy of the test. Currently, fuel cell electrochemical oxygen sensors on the market are more stable than those from Europe and the United States.