Sensor for determining gas components and/or gas concentrations of gas mixtures

Sensor for determining gas components and/or gas concentrations in gas mixtures, in particular of CO, NO.sub.x and HC in exhaust gases of internal combustion engines, said sensor comprising:

• a measuring element having a sensitive regional;
• a pump cell with pump electrodes which are arranged on a solid electrolyte, with the pump electrodes causing a transfer of oxygen to the measuring element by utilizing the oxygen ion conduction of the solid electrolyte;
• and, a diffusion path for the gas mixture and the oxygen pumped by the pump cell, with the gas mixture and the pumped oxygen being carried to the sensitive region of the measuring cell via the diffusion path;
• and wherein:
• an electrode of the pump cell is disposed in the diffusion path and is arranged in the direction of the gas mixture downstream of the sensitive region of the measuring element so that a concentration gradient of the gas component to be determined and an oxygen concentration gradient are formed in the diffusion path and run counter to one another;
• and, the measuring element is arranged in the diffusion path relative to the gradients such that the oxygen concentration present in the sensitive region of the measuring element is larger than the concentration of the gas component to be determined in the sensitive region so that the measuring element is located in a region of high sensitivity relative to the gas component or gas components to be determined.