Great enhancement of the ratio of output signals of the resistance type sensors by a double sensors circuit

We proposed a simple double sensor circuit to enhance the ratio of output signals of the resistance type sensors. In this circuit, one sensor (sensor 1) is used to control the current through another sensor (sensor 2). Thus, when the environment atmosphere is changed, both the resistance and the current through sensor 2 are changed and result in a great enhancement of the ratio of output signals. Resistance oxygen sensor YBa 2Cu 3O 7− x (YBCO) was used to demonstrate this proposal. Actually, it shows that the ratio of output signals increase from 20 to 360.