Voltameter, Weight.
A voltameter in which the amount of decomposition is determined by
weighing the products, or one of the products of the electrolysis. The
titles Voltameter, Copper, and Voltameter, Silver, may be cited.
Fig. 343. WEIGHT VOLTAMETERS.
In the cuts are shown examples of weight gas voltameters. These are
tubes light enough to be weighed when charged. Each contains a
decomposition cell T, with its platinum electrodes, and charged with
dilute sulphuric acid, while t is calcium chloride or other drying agent
to collect any water carried off as vapor or as spray by the escaping
gases; c are corks placed in position when the weighing is being
executed, so as to prevent the calcium chloride from absorbing moisture
from the air.
In use the tubes are weighed. They are then connected to the circuit,
after removal of the corks, and the decomposition proceeds. After a
sufficient time they are removed, the corks put in place, and they are
weighed again. The loss gives the water decomposed.
The water corresponding to one coulomb is
.09326 milligram .001430 grain, Ayrton,
.092 " Hospitalier,
.0935 " Daniell.