| 摘要 |
Gravimetric apparatus is provided to mechanically adjust the internal capacity of a volumetric liquid dispensing cavity, such as a metering cavity, to compensate for decrease in density and expansion of said liquid at ambient temperatures above the temperature of maximum density of said liquid. The apparatus includes a liquid displacing member, preferably in the form of an elongated bar which is inserted into the liquid metering cavity to decrease the volumetric capacity thereof, and which may be moved manually or automatically inwardly or outwardly of the cavity to vary the capacity of the cavity in such a manner that it will always contain a volumetric charge of liquid having a weight equal to the same charge of liquid at its maximum density. Automatic control of the liquid displacement member is provided by a temperature sensing element which monitors the temperature of the liquid during the metering operation and transmits such information to a microcomputer having a memory in which the temperature/density function characteristics of the liquid is stored. The microcomputer is operatively coupled to the temperature sensing element for moving it in selected increments.
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