Gas collecting tube

The terms gas-collecting pipe, the double valve and gas tube mouse describe an elongated gas-tight container having a valve at each end. Generally such a container has a calibrated volume of a cylindrical shape and is made ​​of glass. Gas collection pipes are commonly used for scientific purposes for collecting gas samples.

• Gas collecting tubes made ​​of glass, cylindrical, with two olives
• As above, but with two glass taps, without septum
• As before, with septum
• As before, but with PTFE stopcocks, without septum
• As before, with septum

Gas collection tubes are available with a content of 150, 250, 350, 500, and 1,000 ml

Application: A method for measuring the mass density of a gas

The mass density of a gas can be determined with the following devices: a gas manifold, a laboratory balance and a water pump.

Mass and volume of a gas are extracted amount determined: under the atmospheric pressure, the gas to be analyzed is introduced into the gas manifold and then determines the total mass. Then the water pump sucks a large portion of the gas from the gas manifold, the resulting thereafter total mass is also measured. The difference between the two readings gives the mass of the exhausted gas. Last is the almost evacuated gas collection pipe enables to suck up a degassed liquid (usually pre- heated water ). This is again at atmospheric pressure. For the last time the now completely filled with liquid gas collection tube is weighed. The mass difference of almost evacuated tube and the liquid-filled gas collection pipe gives the mass of the aspirated fluid, which has taken the place of the exhausted gas. The given mass density of the liquid makes it possible to calculate the displaced volume.

This are the mass and the volume of the extracted amount of gas available, which makes the mass density be calculated at atmospheric pressure. If the gas is a basic substance, then allows the state equation to determine the molar mass of the gaseous chemical substance: ( represents the universal gas constant and the absolute temperature at which the measurements were made ).