Method for determining the temperature of a solid electrolyte gas sensor

Abstract

The invention relates to a method for determining a temperature of a sensor (110) for detecting at least one property of a measuring gas in a measuring gas chamber. The sensor (110) comprises at leastone sensor element (112) for detecting the property of the measuring gas. The sensor element (112) comprises at least one first electrode (116), at least one second electrode (118), and at least onesolid electrolyte (114) connecting the first electrode (116) and the second electrode (118). The sensor (110) comprises at least one electronic control unit. The method according to the invention comprises the following steps: regulating an operating state, wherein a heating voltage is applied to the sensor element (112), and a substantially constant voltage state on the sensor element (112) is regulated and recorded; a) carrying out at least one diagnosis sequence, wherein at least one first diagnosis state (144) is regulated by applying a diagnosis current to the sensor element (112), and atleast one second diagnosis state (146) is regulated, in which the diagnosis current is cut off, at least one first voltage value being detected in the first diagnosis state (144) and at least one second voltage value being detected in the second diagnosis state (146); and b) determining information about the temperature from the first voltage value and the second voltage value, and the constant voltage state of the operating state.

Description

Background technique [0001] Numerous sensors and methods for detecting at least one property of the measurement gas in the measurement gas space are known from the prior art. In principle, the measurement of any physical and / or chemical properties of the gas can be involved, wherein one or more properties can be detected. In the following, the invention is described in particular with reference to the qualitative and / or quantitative detection of the fraction of the gas component of the measurement gas (in particular with reference to the detection of the oxygen fraction in the measurement gas fraction). For example, the oxygen fraction can be detected as a partial pressure and / or as a percentage. Alternatively or additionally, however, other properties of the measurement gas can also be detected. [0002] In particular, ceramic sensors are known from the prior art which comprise sensor elements which are based on the use of determined electrolytic properties of solids (ie ba...

AI Technical Summary

Problems solved by technology

On the one hand, this strong polarization can lead to further distortion of the resistance measurement

On the other hand, in the case of steering by means of a current source, this polarization and thus the ohmic voltage shift on the Nernst cell may (in the closest case) be proportional to the resistance and current magnitude, so that on a ceramic Increased likelihood of irreversible processes occurring and sensor element may be permanently damaged

In the event of sensor aging or damage, the sensor electrode capacitance may decrease, which in turn may lead to polarization of the electrodes and lead to additional distortion of the resistance measurement

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