Patent ID: 8302459

Claim:
A thermal conductivity sensor that detects a thermal conductivity of a sample gas by using a Wheatstone Bridge circuit constructed in such a manner that measurement resistors that are brought into contact with the sample gas are disposed on a first opposing side, and reference resistors that are brought into contact with a reference gas are disposed on a second opposing side, and comparing the potential difference between connection points of the reference resistors and the measurement resistors, wherein the measurement resistors disposed on the first opposing side are assembled in one measurement space in which the sample gas is housed, and the reference resistors disposed on the second opposing side are assembled in one reference space in which the reference gas is housed, wherein the measurement resistors disposed on the first opposing side are made of two thin film resistor bodies formed on one substrate surface, and the reference resistors disposed on the second opposing side are made of two thin film resistor bodies formed on one substrate surface.