| 摘要 |
PURPOSE:To maintain electrode performance over a long period of time and to inexpensively supply the sensor having high accuracy by maintaining the surface roughness of the surface at the front end of an inside electrode in a specific range. CONSTITUTION:The sensor has the inside electrode, which is formed by sealing a fine noble metal wire 2 consisting of platinum, etc., into a fine rod consisting of glass, etc., and roughening the surface of the glass, etc. holding the end face of the fine noble metal wire 2, and the gas permeable and liquid impermeable electrode film 1 which holds the thin layer of an electrolyte 7 at the front end of the electrode 6. The thin film holding the electrolyte 7 is extremely small and, therefore, a liquid shortness state arises and the electrode performance is not exhibited if the glass or the like holding the fine noble metal wire 2 is finished to a specular surface of <=1mum surface roughness RMAX. The spacing between the electrode film 1 and the fine noble metal wire 2 increases too much and the delay in response and the linearity defect arise if the surface roughness RMAX exceeds 5mum. The electrode 6 is, therefore, so formed that the surface roughness at the front end of the electrode attains >=1mum and <=5mum. |
