Apparatus for determining deviation of a volume of liquid from a predetermined volume comprises a main vessel (4) for receiving the liquid and a measuring vessel (5) from which the deviation is determined from the meniscus of the liquid in the measuring vessel (5). A communicating tube (49) extending from a neck (32) of the main vessel (4) communicates the main vessel (4) with the secondary vessel (5) through a ball valve (56). Liquid above a weir (55) in the neck (32) flows into the measuring vessel (5). The deviation of the liquid volume is read from a scale (26) adjacent the measuring vessel (5). A variable volume bladder (71) completely filled with liquid alcohol is mounted in the main vessel (4) for compensating for volume changes in the main vessel (4) due to temperature variations.
