Method and apparatus for measurement of the oxygen content or the oxygen partial pressure in a measurement gas

摘要

Method and apparatus for measurement of the oxygen partial pressure or the oxygen content in a measurement gas in at least one measurement cycle using a solid electrolyte cell having at least one oxygen-conducting solid electrolyte, and having at least one reference electrode as well as at least one measurement electrode, wherein the at least one measurement electrode is in communication with the measurement gas and the at least one reference electrode is in communication with a reference gas or reference volume separated from the measurement gas, wherein a current is imposed via the electrodes on the solid electrolyte cell for pump operation and a measurement voltage (UM) is tapped at the electrodes.

主权项

1. A method for measurement of an oxygen partial pressure or an oxygen content in a measurement gas in at least one measurement cycle using a solid electrolyte cell having at least one oxygen-conducting solid electrolyte, and having at least one reference electrode and at least one measurement electrode, wherein the at least one measurement electrode is in communication with the measurement gas and the at least one reference electrode is in communication with a reference gas or a reference volume separated from the measurement gas, the method comprising:
imposing a current via the at least one reference electrode and the at least one measurement electrode on the solid electrolyte cell for pump operation; tapping a measurement voltage (UM) at the at least one reference electrode and the at least one measurement electrode; wherein in a first phase (phase I) of the at least one measurement cycle, an oxygen partial pressure of the reference volume is reduced via the solid electrolyte cell operated in a pump mode until the oxygen partial pressure is lower than an oxygen partial pressure of the measurement gas so that the measurement voltage (UM) used in a measurement phase (phase IV) for determining an oxygen partial pressure or the oxygen content of the measurement gas is only or is substantially only determined by an oxygen partial pressure quotient between the oxygen partial pressure of the measurement gas and an oxygen partial pressure of the reference gas, wherein the oxygen partial pressure of the reference volume is determined by a reference measurement with a known oxygen partial pressure of the measurement gas.