Nach dem polarographischen Messprinzip arbeitende Grenzstromsonde

摘要

A limiting current-type sensor for polarographic measurement is used to determine the oxygen content of gases, in particular in exhaust gases from internal combustion engines. The sensor has an inner pump electrode (2) lodged in a tunnel (4) behind the tunnel inlet region (4'). Both Knudsen and gaseous diffusion take place in a filling (6) with diffusion channels (8, 9) in said tunnel inlet region. The diffusion channels (8, 9) create a diffusion barrier which substantially reduces the temperature and pressure dependence of the sensor.