DEVICE AND METHOD FOR DETERMINING THE CONCENTRATION OF A VAPOR BY MEANS OF AN OSCILLATING BODY SENSOR

摘要

A device and a method determines the concentration of a vapor in a volume, in particular for determining or controlling the mass flow of the vapor being conveyed through the volume by a carrier gas. The device comprises a sensor, which supplies a sensor signal that is dependent on the concentration or partial pressure of the vapor. The sensor has an oscillatory body that can be brought to oscillation, the oscillation frequency of which is influenced by a mass accumulation formed on a surface of the oscillating body by the condensed vapor. The oscillating body has a temperature control unit, by means of which the oscillating body can be brought to a temperature below the condensation temperature of the vapor. An evaluation unit determines the concentration or the partial pressure of the vapor from the temporal change of the oscillator frequency.

主权项

1. A device for determining or controlling a mass flow of a vapor being conveyed through a volume (2) by a carrier gas, wherein the volume (2) can be heated by means of a heating unit (8) to a temperature above a condensation temperature of the vapor, the device comprising a sensor (1), situated in the volume (2), which supplies a sensor signal that is dependent on a concentration or a partial pressure of the vapor, the device characterized in that the sensor (1) has an oscillatory body (17) that can be brought to oscillation, an oscillation frequency of which is influenced by a mass accumulation formed on a surface (18) of the oscillating body (17) by a condensation of the vapor, wherein the oscillating body (17) has a temperature control unit (19, 20), by means of which the oscillating body can be brought to a temperature below the condensation temperature of the vapor, wherein an evaluation unit determines the concentration or the partial pressure of the vapor from a temporal change of the oscillation frequency.