Gas detection apparatus

A gas detection apparatus for detecting a concentration of a target gas in an atmosphere of interest comprising:

• a gas sensor having a solid electrolyte body;
• a pair of electrodes disposed on the solid electrolyte body;
• a heater for heating the solid electrolyte body;
• a change amount calculation section;
• a correction section;
• and
• an oxygen detection section which detects a concentration of oxygen in the atmosphere of interest, wherein
• electric power supplied from a power supply to the heater is controlled by pulse width modulation so as to control a temperature of the solid electrolyte body,
• the concentration of the target gas is detected through use of an electromotive force generated between the pair of electrodes in accordance with the concentration of the target gas,
• the change amount calculation section calculates the amount of a change in the electromotive force caused by a change in an output voltage of the power supply on the basis of the concentration of oxygen detected by the oxygen detection section, and
• the correction section corrects the electromotive force generated in the gas sensor through use of the change amount calculated by the change amount calculation section.