Gasometer

Gasometer (from French gaz-gas and Greek metron-measure), a vessel used in laboratories for collecting (and also for measuring) gas, from which the collected gas can be used as needed. Depending on the properties of the gas being collected (CO, CO₂, Cl, SO₂, H₂, etc.), metal or glass gasometers are used. The figure shows a very common type of laboratory gasometer of the Mitcherlich system—a glass vessel with metal connecting parts, with a capacity of 16 liters. To use it, it is first filled with water through funnel A, after previously opening taps a and b; then these taps are closed, the screw cap c is removed, and gas is admitted from the gas generator through tube b. As gas is admitted, water flows out of the lower opening. When the vessel is filled with gas, the screw cap is screwed back on and tap b is closed. When tap a is opened, water flows from the funnel into the vessel, and the gas, acquiring pressure corresponding to the water column, is displaced through tube b and used as needed. Due to the transparency of the vessel, the amount of gas in the gasometer can always be determined by the layer of water. In metal gasometers, which are built on the same principle, water gauge tubes run the full height of the vessel for this purpose. Gases that are strongly absorbed by water, for example sulfur dioxide, are collected not over water but over mercury. For this purpose, small mercury gasometers of Bunsen are convenient. For collecting chlorine, "chlorine gasometers" are used, similar to the one shown in the figure, however, made without metal parts, exclusively of glass, with ground glass parts.

For collecting chlorine, "chlorine gasometers" are used, similar to the one shown in the figure, however, made without metal parts, exclusively of glass, with ground glass parts.