A beam of light is passed through the absorption cell (3) as well as through a reference cell (4) containing a reference gas.
The second electrode (32) is provided in a reference gas area (25) that contains a reference gas.
A measurement gas volume (6) is arranged around the sorption cell (2) for receiving a reference gas, and the reference cell (4) is surrounded by a reference gas volume (8), which is likewise provided for receiving the reference gas.
The reference gas volume is separated from the gas to be measured so as to make at least difficult an exchange of particles between the reference gas volume and the gas to be measured.
The gas sensor also has a reference electrode, exposed to a reference gas, and a sensor heating device.
The solid electrolyte is configured with one side facing the gas being measured and one reference gas side which is separate from the gas being measured.
The solid electrolyte (1) is configured with one side facing the gas being measured and with one reference gas side separate from the gas being measured.
The measurement electrode is in contact with the gas to be measured and is connected through the solid electrolyte to the reference electrode, which is in contact with a reference gas volume.
A reference gas of known oxygen content is passed along bore (5) of an innermost tube (1) and the reference gas comes into contact with electrode (15).