Elaborarea şi studiul unui senzor electrochimic pentru determinarea continuă a oxigenului
Pica Elena Maria
Type oxygen sensor Clark, whose operating principle is based on electrochemical reduction of oxygen on the cathode ( Ag , Pt , Au ) . Following the reduction to give a current which is proportional to the oxygen content of the environment with which it is in contact. Oxygen is reduced at the cathode, according to the reaction: O2 + 2H2O + 4e - = 4HO- , while the reaction of oxidation (dissolution ) of the metal at the anode : Meo - ze = Mez+
The sensor is formed from a silver cathode located centrally surrounded by the electrolyte consisting of an aqueous gel agar - agar + KI, in which the anode Ag / AgCl between the electrolyte and the anode there is an insulating layer. The end contact is covered with a membrane sensor, fixed in a ring . The sensor connects to a portable device, Oximeter via a socket. Signal from the sensor is amplified by an amplifier whose operation is triggered by connecting the battery with a switch and a contact closure switch, analog result given by a measuring. On the same scale can be read and the sample temperature, which is measured by connecting the respective circuits through another switch. Measurement of oxygen sensitivity is achieved by 0 .... 50 % PO2, respectively 0 .... 100 % PO2, adjustable by two switches plaset too, on the oximeters. Check battery is made with another switch and the potentiometer is made of zero point and gain.
CZU: 544.6:546.21-124; 546.21-124