Fuel cell method trace oxygen analyzer
Trace oxygen analyzer (fuel cell electrochemical method)
The use of a completely sealed fuel cell oxygen sensor is one of the current international advanced * oxygen measurement methods. The fuel pool oxygen sensor is composed of a highly active oxygen electrode and a lead electrode, and is immersed in a 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 polymer film. The sample gas does not directly enter the sensor, so the solution and lead electrodes 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 is determined by the number of oxygen molecules diffused into the oxygen electrode, and the diffusion rate of oxygen is proportional to that in the sample gas, oxygen content. In this way, the output signal 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 an external circuit, the charge transfer or the current in the reaction 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, and many sample gas processing systems are eliminated. The trace oxygen analyzer is faster than the old-fashioned “gold-net-lead” primary battery for oxygen measurement, and does not require a long start-up blow-off process. The “gold-net-lead” primary battery sample gas directly enters the solution, resulting in a very high maintenance amount Large, but the fuel cell sample gas does not directly enter the solution, the sensor can work very stably and reliably for a long time. In fact, fuel cell oxygen sensors are completely maintenance-free. However, in the process of use, frequent calibration is required to ensure the accuracy of its test. The fuel cell electrochemical oxygen sensor on the market is more stable than the British CITY sensor.