An apparatus for processing crop, animal feed or components with a drivable tool and at least one NIR sensor system for determining at least feed values, having a scanning head with a spectrometric sensor and at least one light source behind a transparent pane which can be passed by the feed, comprises in a housing of the NIR sensor system a calibration surface, the appearance of which is different from the appearance of the feed to be scanned on the pane, wherein the scanning head is actively adjustable for calibration between a scanning position aligned with the pane and a calibration position aligned with the respective calibration surface.