An agricultural product flow sensor and a flow sensor system for delivery tubes in an air seeder is provided. The flow sensor can include a particulate material sensor for sensing agricultural product passing through a delivery tub, a radio node for transmitting and receiving wireless signals and a wireless power source. The sensor system can use the flow sensors by attaching the flow sensors inline with delivery tubes and near a working tool. The flow sensors can monitor the flow of agricultural product through the delivery tube and transmit flow information to a person operating the air seeder.