Sensor module

A sensor module placeable outside a cap attachable to an opening section of a container containing a content, the sensor module being configured to be housed in a housing,

• the sensor module comprising:
• a sensor section;
• and
• a lens section,
• wherein the sensor section includes:
• a transmission and reception section including:
• a transmitter configured to transmit an electric wave;
• and
• a receiver configured to receive the electric wave;
• and
• a computation section,
• the transmitter transmits an electric wave that passes through the cap into the container,
• the receiver receives a reflected wave resulting from the electric wave being reflected by the content in the container,
• the lens section faces the transmission and reception section and includes a bottom wall that allows passage of the electric wave that the transmitter transmits and the reflected wave, and
• the computation section is configured to compute a remaining amount of the content, based on a time interval from (i) the transmitter transmitting the electric wave to (ii) the receiver receiving the reflected wave.