Method and apparatus for measuring the concentration of an analyte in a liquid sample

摘要

The method involves arranging two capacitive field-effect sensors in a conjoint measuring cell. The sensors are brought into contact simultaneously with a sample liquid (2) or a sample gas. A bias voltage is applied between each sensor and a reference electrode (1) contacted simultaneously by the sample liquid or the sample gas. The bias voltage is composed of an electric direct voltage and a superposed alternating voltage. The capacitance variation caused by the analytes is regulated by controlling the bias voltage applied to the measuring sensor. An independent claim is also included for a device for measuring the concentration of an analytes in a sample liquid or in a sample gas.