Study on The Limit Size Determination Method of The Inlet Hole of The Limiting Current Oxygen Sensor

When the oxygen reaction rate of the limiting current oxygen sensor is smaller than the oxygen diffusion capacity of the diffusion hole, the current drift occurs. Therefore, it is important to determine the size of the diffusion hole of the limiting current oxygen sensor. In this paper, the minimum and maximum sizes of the diffusion hole are calculated successively by substituting the parameters of the limiting current oxygen sensor, and the limiting size of the inlet hole of the limiting current oxygen sensor is derived. The results show that in order to ensure the oxygen diffusion processing free diffusion state of the limiting current oxygen sensor, it is necessary to limit the minimum opening diameter of the inlet hole to 2.5$\mu$m. The stability condition of the oxygen transfer capability of the limiting current oxygen sensor is proposed, and the maximum values of the radii of the inlet and outlet holes of the diffusion hole are 159$\mu$m and 63$\mu$m, respectively.