Automatic measurement of fluid surface level during milking

摘要

The level monitoring apparatus has sensors (31) around the sight glass (11) detect the fluid surface level (35). Source (36,38) separated by a distance (a) transmit light to detectors (37,39). The sensor assembly is driven (arrow A) on a slide ((26) until only the lower beam is impeded by the fluid in the tube. An accuracy of 0.1 mm is achieved over a working range of 600mm. The sight glass is connected to a cooled vat into which the cow is milked. The sensors detect when the milking process has ceased. They then trigger valves to decant the milk into bulk storage under a differential air pressure of 1 bar.