A process for analysing bulk quantities of grain in-line and separating the grain into batches, each batch corresponding to at least one pre-selected grain parameter value, the processing including: delivering the grain continuously past an in-line measurement station, analysing the grain by emitting light onto the grain passing the in-line measurement station and detecting the light reflected from the grain to provide a spectrum of the grain, converting the spectrum into the or each parameter value, and separating the grain in-line into batches in response to the or each measured grain parameter value, the process including controlling grain flow through the measurement station for forming an optically dense grain layer at the measurement station for reflecting the light emitted onto the grain, characterised in that the process includes funnelling the grain for delivering the grain in an optically dense grain layer stream past a sensor unit at the measurement station, delivering the grain through an infeed chute having the sensor unit mounted at a side wall of the infeed chute at the measurement station, passing grain delivered through the infeed chute through a funnel mounted on the side wall at the sensor unit, forming the optically dense grain layer by means of the funnel and delivering the grain in an optically dense grain layer stream against the side wall past a sensing head of the sensor unit mounted on the side wall, channelling the grain between tapered funnel side walls (23, 24) projecting outwardly from the side wall of the grain infeed chute at which the sensor unit is mounted and between an angled guide flap and the chute side wall, the angled guide flap extending between the funnel side walls (23, 24) and spaced-apart from the chute side wall at which the sensor unit is mounted, said angled guide flap tapering inwardly from an inlet of the funnel towards the chute side wall on which the sensor unit is mounted. delivering the grain continuously past an in-line measurement station, analysing the grain by emitting light onto the grain passing the in-line measurement station and detecting the light reflected from the grain to provide a spectrum of the grain, converting the spectrum into the or each parameter value, and separating the grain in-line into batches in response to the or each measured grain parameter value, the process including controlling grain flow through the measurement station for forming an optically dense grain layer at the measurement station for reflecting the light emitted onto the grain, characterised in that the process includes funnelling the grain for delivering the grain in an optically dense grain layer stream past a sensor unit at the measurement station, delivering the grain through an infeed chute having the sensor unit mounted at a side wall of the infeed chute at the measurement station, passing grain delivered through the infeed chute through a funnel mounted on the side wall at the sensor unit, forming the optically dense grain layer by means of the funnel and delivering the grain in an optically dense grain layer stream against the side wall past a sensing head of the sensor unit mounted on the side wall, channelling the grain between tapered funnel side walls (23, 24) projecting outwardly from the side wall of the grain infeed chute at which the sensor unit is mounted and between an angled guide flap and the chute side wall, the angled guide flap extending between the funnel side walls (23, 24) and spaced-apart from the chute side wall at which the sensor unit is mounted, said angled guide flap tapering inwardly from an inlet of the funnel towards the chute side wall on which the sensor unit is mounted.