SU618647A1

SU618647A1 - Thermal level gauge

Info

Publication number: SU618647A1
Application number: SU762425894A
Authority: SU
Inventors: Евгений Андреевич Синебоков
Original assignee: Sinebokov Evgenij A
Priority date: 1976-12-03
Filing date: 1976-12-03
Publication date: 1978-08-05

Description

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3 дам фазочувствительного усилител со встроенным преобразователем напр жени в угол поворота. Уровнемер работает следующим образом. Величины сопротивлений 4 и 6 завис т от температуры нагрева, температуры среды, и коэффициента теплопередачи, который будет разным в газовой и жидкой средах. На величину сопротивлени 5 кроме указанных выше факторов вли ет положение уровн . При изменении уровн мен етс сопротивление 5, на входе усилител 9 возникает напр жение разбаланса, которое в зависимости от его фазы отрабатываетс усилителем , и по положению движка реохорда суд т о положении уровн . Наличие терморезисторов 4 и 6, подключенных к концам реохорда исключает погрешность от изменени температуры, а также от изменени характеристик нагревательного элемента и колебаний напр жени питани , так как, например, изменение температуры приводит к изменению отношени сопротивлений 6 и 4, но одновременно считаетс и отношение сопротивлени погруженной и непогруженной частей измерительного датчика 5.3 ladies phase-sensitive amplifier with built-in voltage converter in the angle of rotation. The gauge works as follows. The magnitudes of the resistances 4 and 6 depend on the heating temperature, the medium temperature, and the heat transfer coefficient, which will be different in gas and liquid environments. The resistance value 5, in addition to the factors mentioned above, is influenced by the position of the level. When the level changes, the resistance 5 changes, an unbalance voltage arises at the input of amplifier 9, which, depending on its phase, is processed by the amplifier, and the position of the level of the rheochord is judged on the position of the level. The presence of thermistors 4 and 6, connected to the ends of the rail, eliminates the error of temperature changes, as well as changes in the characteristics of the heating element and fluctuations in the supply voltage, since, for example, a change in temperature leads to a change in the ratio of resistances 6 and 4, but the ratio resistance of immersed and non-immersed parts of the measuring sensor 5.

Claims

-618647 Formula of the invention Thermal level gauge containing thermistor sensors, one of which is measuring and two compensatory sensors, has a common point installed in one housing with a heating element so that compensation sensors are placed above and below the measuring sensor, differential bridge circuit, reference source voltage, power regulator and secondary measuring device, characterized in that, in order to reduce the temperature error, the secondary device is designed as a phase-sensitive preamplifier with a voltage converter to the angle of rotation and the slide wire, whose inputs are connected to outputs of the compensation sensors, the movable contact slide wire and output of the measuring sensor are connected to the inputs of a phase-sensitive amplifier. Sources of information taken into account in the examination: 1. USSR author's certificate No. 491035, cl. G 01 F 23/22. 1973.

2. USSR author's certificate number 540149, cl. G 01 F 23/22, 1975.