The Isoteniscope is a glass apparatus, which is used to determine the vapor pressure of liquids.

The difficulty of such a measurement is due to the fact not to let the pressure gauge come in contact with the corrosive or otherwise hazardous substance under certain circumstances, and on the other to keep the whole room filled with steam gas isothermally. This solves the problems Isoteniscope elegant.

The test liquid is in a glass flask. This is connected to the pressure measurement using a U-tube, in whose drain is likewise to the test substance. This U- tube serves as a relative pressure gauge between the isothermal gas space and the outer space where there is a reflux condenser and the ( absolute measurement ) pressure gauge. The outer space are also connected a gas supply and a pump.

Now changed by changing the temperature of the isothermal gas space of the vapor pressure of the liquid, as the liquid level changes in the U- tube. He can be compensated in the outer space through appropriate supply or pumping of neutral gas; the pressure in the outer space then again corresponds to the pressure in the interior. The gas pressure in the interior space can therefore be determined by the measurement of the (identical) pressure in the outer space.

  • Thermodynamics
  • Pressure gauge