Method for calibrating a tailings return sensor in a combine harvester

A combine harvester comprising (i) crop processing systems, (ii) a tailings return sensor for measuring an amount of crop material in a tailings return system, and (iii) a controller, operatively coupled to the crop processing systems and the tailings return sensor, that is configured to perform a method of calibrating the tailings return sensor for measuring an amount of crop material in the tailings return system of the combine harvester, the method comprising the consecutive steps of:

• harvesting a crop with the combine harvester in a first configuration,
• ceasing to harvest the crop while continuing to operate the crop processing systems of the combine harvester,
• determining a first run-empty parameter, representative of a first amount of the crop that is processed by the combine harvester after ceasing to harvest the crop,
• resuming harvesting the crop with the combine harvester in a second configuration, the first configuration and the second configuration being designed to cause a different amount of crop material in the tailings return system,
• ceasing to harvest the crop while continuing to operate the crop processing systems of the combine harvester,
• determining a second run-empty parameter, representative of a second amount of the crop that is processed by the combine harvester after ceasing to harvest the crop, and
• calibrating the tailings return sensor based on the first run-empty parameter and the second run-empty parameter.