Gas sensor control unit

A gas sensor control unit adapted for connection to plural gas sensors including at least first and second gas sensors, comprising:

• first and second signal-detection circuits for detecting first and second gas-detection signals and first and second internal resistance signals of the first and second gas sensors, respectively;
• a signal-switching and outputting circuit for receiving signals including said first and second internal resistance signals, said signal-switching and outputting circuit switching the signals including at least said first and second internal resistance signals, and outputting at least one of the switched signals from the signal-switching and outputting circuit to an external apparatus;
• and
• a switched-signal controlling circuit for controlling said signal-switching and outputting circuit and specifying the signals to be switched and outputted from the signal-switching and outputting circuit to the external apparatus.