Combine with a bypass device

A method for performing one or both of cleaning or referencing an optical measuring device of a self-propelled combine, the method comprising:

• operating the combine, the combine:
• comprising a grain elevator configured to convey a flow of harvested material from a conveying and cleaning device of the combine to a grain tank of the combine;
• and
• a bypass device positioned at or relative to the grain elevator and configured to guide a partial flow of the harvested material that comprises at least a part of the flow of harvested material conveyed through the grain elevator, wherein the bypass device includes an optical measuring device configured to determine one or more harvested material properties of the partial flow of harvested material;
• determining, by the optical measuring device, whether to perform one or both of cleaning or referencing;
• and
• transmitting, by the optical measuring device, one or both of a cleaning signal or a referencing signal to at least a part of the combine responsive to determining to perform the one or both of cleaning or references;
• and
• responsive to detecting, by the at least a part of combine, the one or both of the cleaning signal or the referencing signal, performing one or both of:
• cleaning of the optical measuring device using the bypass device;
• or
• configuring at least a part of the combine in order to prevent inflow of the partial flow of harvested material into the optical measuring device and performing, at least partly while the inflow of the partial flow of the harvested material is prevented, at least one operation to reference the optical measuring device.