Verfahren und Vorrichtung zum Messen und Steuern eines Flüssigkeitsdurchflusses.

摘要

A part of a tube (1A), through which a fluid passes, is cooled by means of an electronic cooling element (2) and a flow rate of said fluid is measured on the basis of the temperature of a surface of said cooled tube (1). Not only the flow rate of the fluid flowing through the tube (1) can be determined in a contactless manner and a very small flow rate of the fluid can be determined but also the tube (1), through which the fluid passes is cooled by means of the electronic cooling element (2), so that no bubbles are generated. Thus the measurement of the fluid, which is apt to generate gases, such as low boiling point liquid, is possible. In addition, the measurement is not influenced by gases dissolved in the fluid and merely the temperature difference resulting from the flow of the fluid, that is the rise of the temperature of the fluid, is detected to prevent the measurement from being influenced by the assembling position of the flow meter, so that the high-precision measurement is possible. Consequently, a stable and sure controlling of the flow rate is possible.