NON-CONTACT PASSIVE FLOWMETERS OF LIQUIDS AND GASEOUS OR FRIABLE SUBSTANCES

摘要

Mechanical meters cease to function at low flows, each of these meters also have moving parts that are subjected to wear and tear. Also these parts can react with flowing substances, changing composition of both. Magnetic, ultrasonic, capacitive and vortex flowmeters (FMs) require introducing some electrical or optical energy into measuring medium, which can interfere between them. Moreover, the bloodflow (BF) should be tapped on the external area for hemoglobin measuring [1]. (1) the known FMs have some disadvantages There are known methods and devices for measuring the volume flow of a liquid, gasiform and friable substances, and also the blood flow (BF) and hemoglobinum level into it. They are based on the principles of a propeller turning during the contact with a liquid or gas [2, 3], and inducing a voltage during moving the conductor- liquid or blood- in the magnetic field (MF) [2,4,5], and also other physical effects [6-9]. Magnetic resonance phase velocity mapping is a non-invasive technique that can measure the flow velocity in any spatial direction in an imaging slice [10]. This technique has wide application in the clinical field in quantifying blood flow, as well as in non-biomedical areas. The disadvantages of these methods are necessity of placing the head transducer into the flowing medium and introducing into it the additional electrical or other kind of energy. In such case, the acquired data of measurement is not authentic, without additional influence on the substances or tissues.