There is not a button to reset the WiFi network connection.  To make the sensor network, AirMonitor_xxxx, visible again you will need to turn off the WiFi network or take the sensor out of range of the WiFi network the sensor is currently configured to.  Once sensor network is broadcasting again, you will be able to connect it to a different network. Just make sure the WiFi network it is currently installed on remains out of range/offline until it is successfully configured to the new network.