Sensor arrangement for detecting grains in a material stream containing grains and non-grain components in a combine harvester

A combine harvester comprising:

• a chassis;
• wheels coupled to the chassis;
• a crop processing device configured to process crop material;
• a conveyor configured to receive crop residue from the crop processing device, the conveyor including:
• a housing defining an outer circumference, the housing including:
• an inlet configured to receive the crop residue;
• and
• an outlet configured to discharge the crop residue, the conveyor configured to produce a material stream from the crop residue received into the housing;
• and
• a sensor arrangement including:
• an electro-optical sensor arranged on the outer circumference of the housing and configured to view the material stream and generate a signal, and
• an electronic processing device configured to process the signal to detect grains in the material stream,
• wherein the electro-optical sensor is arranged at a downstream region of the housing.