Patent ID: 7279133

Claim:
A planar oxygen sensor comprising a gas sensing arrangement comprising a pump cell, a reference cell spaced apart from the ground cell, and a sensor chamber disposed between the pump cell and the ground cell, a heating device proximate to the gas sensing arrangement for heating the gas sensing arrangement to an operating temperature, said heating device comprising a first heating device lead and a second heating device lead, said second heating device lead being adapted to be connected to a power terminal of a power source, a ground plane electrode adapted for temperature measurement and comprising a first lead, a second lead, and a temperature sensing portion electrically interconnecting the first lead and the second lead, said temperature sensing portion having an electrical resistance indicative of temperature, wherein at least said first lead is disposed between the gas sensing arrangement and the heating device and is electrically connected to said first heating device lead, said first lead having a surface area greater than the temperature sensing portion and an electrical resistance less than the electrical resistance of the temperature sensing portion, an isolation layer disposed between the ground plane electrode and the heating device; a ground terminal connected to the first lead and the first heating device lead, a resistance measurement terminal connected to the second lead, and a power terminal connected to the second heating device lead, whereby the ground terminal and the resistance measurement terminal are adapted to be connected to an electrical circuit for measuring the electrical resistance therebetween, said electrical resistance being indicative of temperature, and whereby said power terminal and said ground terminal are adapted to be connected to a power source for providing electrical current to the heating device.