SENSORELEMENT FUER GRENZSTROMSENSOREN ZUR BESTIMMUNG DES (LAMBDA)-WERTES VON GASGEMISCHEN

摘要

A sensor element (1) for limit current sensors for determining lambda -values of mixtures of gases, in particular exhaust gases of internal combustion engines, comprises a solid electrolyte cell (5) consisting of a pair of electrodes (3) and (4) arranged on a solid electrolyte support (2). The measurement gas enters the inner electrode (3) through a diffusion channel (6). The sensor element also comprises strip conductors for the electrodes (3) and (4), to which a voltage can be applied. This sensor element permits a substantial reduction in the response time in a predetermined length of the diffusion channel (6). To this end, an additional pump cell (9), shown in Figure 5, is provided. The response time can be reduced by means of the additional pump cell (9) to less than a quarter of that obtained with sensor elements without an additional pump cell. In addition, the signal range can be doubled by reversing the sign without increasing the current flowing through the electrodes (3) and (4).