| 摘要 |
A system for dispensing a liquid, which may be corrosive, in an amount which is substantially fixed for each cycle of operation includes an airtight measuring vessel with an inlet conduit through which liquid is introduced unidirectionally and an outlet or discharge conduit through which the measured amount of liquid is dispensed. The outlet conduit extends to a predetermined level within the vessel and above it is a float/valve mechanism operating in association with an airjet pump. The operation is such that when the float is buoyed to an operative level higher than the predetermined level, conditions are changed within the vessel to commence the dispensing cycle which terminates when the level of liquid falls below the predetermined level whereupon the float/valve drops to an unbuoyed position to commence the next filling cycle. Operation of the jet pump is required during cycling to cooperate with the float/valve mechanism and create the conditions necessary for filling and for dispensing.
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