Sensor control apparatus and sensor control system

A sensor control apparatus configured for connection to a gas sensor, the gas sensor including an oxygen pump cell having a solid electrolyte body, a first electrode formed on one surface of the solid electrolyte body, and a second electrode formed on the other surface of the solid electrolyte body and which detects a particular gas component contained in a gas under measurement, the sensor control apparatus comprising:

• voltage application means for applying a first application voltage, a second application voltage, and a third application voltage, in this order, to the oxygen pump cell, the first application voltage being a voltage at which moisture contained in the gas under measurement does not substantially dissociate and which is used when the particular gas component is detected, the second application voltage being a voltage at which moisture contained in the gas under measurement dissociates, and the third application voltage being lower than the first application voltage;
• pump current detection means for detecting pump current flowing through the oxygen pump cell;
• and
• control means for detecting humidity of the gas under measurement based on a difference between the pump current when the first application voltage is applied to the oxygen pump cell and the pump current when the second application voltage is applied to the oxygen pump cell.