Bottle contg. photographic developer or similar chemicals - where height at which opaque bottle floats in test liq. is used to indicate vol. of chemical left in bottle

摘要

The bottle can float in a test liq. which may be a water bath used to control the temp. of the chemical in the bottle; and one of the walls of the bottle is provided with a graduated scale indicating the vol. of chemical in the bottle. When the bottle is placed in a test liq. or water, the extent to which it floats is determined by the Archimedean pressure; and the level of the test liq. is used as a reference mark to read the graduated scale. When the bottle is full, it will sink to a much greater depth in the test liq. than when it is partly or completely empty, i.e. the depth is proportional to the amt. of chemical in the bottle. This fact is used in constructing the graduated scale. The bottle may be made of an opaque polymer. A photographic developer soln. sensitive to light is kept, e.g. in an opaque, black polymer bottle, so the contents are invisible. But the invention indicates the amt. of liq. left in the bottle.