A grain loss gauging system for a combine harvester uses a collection pan for releasable attachment to a combine harvester in which the collection pan defines a receptacle having an open top for receiving material blown out of the combine harvester when deposited on the ground. A pair of electromagnets and a controller for selectively supplying electrical power to the electromagnets from a battery are supported on the collection pan to electromagnetically retain pan on a vehicle body of the combine harvester. A remote used remotely from the collection pan can be triggered to generate a wireless trigger signal received by the controller to interrupt the electrical power to the electromagnets and release the electromagnets, the controller, and the battery together with the collection pan from the body of the combine harvester. The combine harvester is adjusted to reduce the amount of grain collected in the pan.
