| 摘要 |
FIELD: measurement equipment. ^ SUBSTANCE: invention is related to controlling and measuring equipment and may be used for continuous control of liquid level in closed reservoirs, which are pressurised, in technological processes of chemical, oil, food and other industries. Ultrasonic level metre comprises at least one pair of converters - radiating and receiving accordingly for excitation and reception of antisymmetric acoustic Lamb wave in wall of reservoir, which is partially filled with liquid, installed on outer surface of reservoir, and also high-frequency generator and unit of registration. Unit of synchronisation is also introduced, being joined to unit of registration and high-frequency generator, frequency f of which is related to thickness of reservoir wall h by the following ratio: f=(3-6)/ h. Radiating and receiving converters are installed on reservoir surface via matching prisms made of polyurethane. In order to excite and receive antisymmetric Lamb waves, phased antenna arrays may be used, which consist of chain of converters arranged directly on reservoir wall. Radiating and receiving converters are located on one vertical line in upper and lower permissible levels of liquid accordingly. Level metre may be equipped with the second unit of registration with additionally installed second pair of converters, besides the first and second pairs are arranged along vertical line parallel to each other and are installed in upper and lower permissible level of liquid accordingly parallel to its surface, and both units of registration are synchronised with single unit of synchronisation. ^ EFFECT: improved accuracy of measurement. ^ 5 cl, 5 dwg |
