SU694793A1 - Hydrostatic densitometer - Google Patents

Description

The invention relates to a measuring technique and can be used to measure the density or concentration of liquid media, for example, saline waters of hydroamelioration.

A density meter is known that contains a constant level vessel, at the bottom of which a membrane is fixed, on the other side of which a chamber with a compensating tube of fG is mounted.

The disadvantage of such a density meter is the generation of an analog type output signal.

The closest to the invention in its technical essence is a density meter with a discrete output signal, including a constant level vessel, in the lower part of which a membrane is fixed, on the other side of which a variable volume chamber with a compensating tube, an actuator, and an indicator connected to a time interval meter consisting of a trigger, a key, a generator and a counter. impulses 2.

In this meter, the density value is converted into a time interval by changing the pressure of the reference liquid at a constant speed, and then into a number of pulses, which is proportional to the measured density. In addition, in a densitometer, a device for providing a pressure build-up of a reference liquid, consisting of a variable volume chamber and an actuator, is difficult in its design solution and doesn’t ensure the linearity of the pressure build-up function of the reference liquid. As a result, the measurement accuracy is reduced.

The purpose of the invention is to increase the measurement accuracy by ensuring the linearity of the increase in pressure of the reference medium.

This goal is achieved by the fact that the hydrostatic density meter is equipped with an electropneumatic transducer and a pneumatic valve, the second chamber is made with a constant volume and is connected to a pneumatic valve and an electropneumatic transducer connected to the generator.

The drawing schematically shows a plate number.

Claims (2)

The density meter consists of a vessel / constant level with inlet 2 and outlet 3 nozzles. At the bottom of the vessel / membrane 4 is fixed, on the other side of which a compensation chamber 5 is installed, filled with a constant volume. The minimum density indicator 6 is connected to the cavity of the chamber 5, and the indicator 7 is connected to the membrane 4, with the indicators 6 w. 7 are connected to the trigger input 8, the output of which is connected via a switch 9 with a counter of 10 pulses. The pulse generator 11 is connected to a 9 l key via an electropneumatic transducer 12 to the closed cavity of the chamber 5. The interrogation button 13 is intended for switching the density meter into operation. A pneumatic valve 14 serves to communicate the cavity of the chamber 5 with the atmosphere. Densitometer works as follows. Under the action of the hydrostatic pressure of a constant level of the controlled fluid, the membrane 4 bends towards the chamber 5, through which the open pneumatic valve 14 communicates with the atmosphere. When the polling button 13 is turned on, the pulse counter is reset, the pneumatic valve 14 is closed and the pulse generator // is turned on. The pulses generated by the generator // are converted by a pneumatic converter 12 into pressure pulses, with the result that a certain amount of air enters the cavity of chamber 5. When the value of pressure in chamber 5 is reached, the indicator 6 triggers, the latter tilts trigger 8, which changes from the On position. At the trigger output, a signal appears that opens the key I, which passes pulses generated by generator 11 to counter 10, and the counting begins. The process of filling the chamber 5 with air takes place until the pressure in it is comparable to the pressure of the hydrostatic column of the analyzed liquid in the vessel. At that, the indicator 7 is activated and, by its signal, the pneumatic casing 14 is simultaneously triggered, together with the cavity of the chamber 5 with the atmosphere, and the trigger 8, which returns to the position 0. As a result, the key 9 is closed and the counting of pulses by the counter 10 stops. The number of pulses recorded by the meter will be proportional to the number of pressure pulses received through the inverter 12 from the generator // from the moment indicator 6 is turned on until indicator 7 is triggered and, consequently, the hydrostatic pressure of the controlled fluid is balanced by the pressure of compressed air in chamber 5, i.e. The measured density of the test liquid. When used as a generator of a pneumatic type generator, its output is directly connected to chamber 5, and to key 9 through a pneumo-electric converter. Thus, in the proposed device, the pulse generator 11 simultaneously performs the role of an actuator, i.e., a source of stepwise compensation compensation pressure in chamber 5, and a source of discrete values (quanta) of the measured density. This makes it possible to synchronize the stepwise increase in the compensation pressure with the pulses detected by the counter 10, in view of which the accuracy of the density meter is improved. Claims of Invention A hydrostatic densitometer containing a vessel divided by a membrane into two chambers, one of which is made constant and filled with the test medium, and the second, made with a variable volume, fitted with a bellows and filled with a reference medium, indicators connected to a time interval meter that includes trigger, key, generator and pulse counter, characterized in that, in order to improve measurement accuracy by ensuring linearity of the pressure increase of the reference medium, it is equipped with An evacuator and a pneumatic valve, the second chamber is made with a constant volume and is connected to a pneumatic valve and an electropneumatic converter connected to the generator. Sources of information taken into account in the examination: 1. US Patent No. 3190124, cl. 73-438, 1970. 2. USSR author's certificate number 5421.21, cl. G 01 N 9/26, 1975.