Appts. for determining the specific gravity of solid objects by volumetric measurement operates on the principle of flooding the object, instead of immersing it. A cylinder and sliding piston, together with a further removable cylindrical lid is used. In a first operation the lid is pushed down over the piston, the piston descending also into the cylinder, until the magnetic rings come into accurate contact. This determines the accurate geometry of the appts. and the contained liq., typically distilled water, now floods the entire internal vol. through the communicating duct, and ascends a certain way up the narrow calibrated pipe at the top. The reading on the scale is taken. From the known weight of the object, its density can be accurately calculated. Economical and small appts. for very accurate measurement of the vol. of valuable articles e.g. gold, silver, jewels etc. Surface tension of the liq. does not affect the result, since the only exposed surface is the very small area within the calibrated tube. Problems arising from bubbles adhering to the object disappear. The entire procedure takes only a few seconds.
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