Method and measuring system for determining and/or monitoring a phase change of a measuring medium in a thermal flow meter

摘要

The method involves determining a phase boundary of a part of a measuring medium i.e. dry gas, using temperature, chemical composition, and partial pressure and/or total pressure of the measuring medium. A measuring signal is provided from a temperature difference between temperature sensors of a thermal flow meter and/or from a thermal output supplied to the measuring medium. Disturbances in the measuring signal of specific type are identified as an aggregate modification state of the measuring medium at the flow meter when the part of the measuring medium is in a region of the boundary. Independent claims are also included for the following: (1) a method for correcting disturbances of specific type in a measuring signal of a thermal flow meter (2) a thermal flow meter for determining and/or monitoring flow of a measuring medium by a measuring pipe, comprising a temperature sensor.