SU569899A1 - Viscosimeter - Google Patents

Description

one

The invention relates to devices for studying the physicochemical properties of substances, in particular to devices for measuring viscosity, density, and concentration of zhitsky products, and can be used in paints, petrochemical and food industries.

A device with temperature measurement using two thermistors, which are included in a bridge circuit, is known, while the temperature difference is measured by a recording potentiometer included in the Msta G1 diagonal.

In these devices there are one two thermistors installed along the flow at the end of the capillary and at the wall of the measuring chamber. The voltage imbalances of these circuits are connected towards each other and in series with the output voltage.

A device for thermal compensation of concentration meters - densitometers 21.

To compensate for the effect of temperature on the measurement result, two chambers are provided in the float device, connected by a narrow channel p filled with a special liquid, and one of the chambers has one elastic wall.

In these devices, thermal compensation is carried out based on the use of thermistors and bridge circuits. Basically, these devices consist of a viscosity gauge of a measuring circuit and a pressure compensation circuit consisting of two or more unequally balanced bridges, each of which is designed as a two-terminal circuit with one thermistor, which has two ohmic resistances.

The disadvantage of such devices is the large error of the thermal compensation schemes when the magnitude of one and the perturbations of the fluid concentration changes within wide limits. The error of some of these devices reaches 20%. All these schemes are suitable for compensating for temperature effects in narrow ranges of concentration changes.

The closest to the proposed device is a pressure compaction device containing a pneumatic type viscosity sensor with a liquid metering system, an amplifier, a logarithmometer, a temp sensor.

permaturm, adder and secondary device, which is connected to the output of the adder 3.

The purpose of the invention is to improve the accuracy of viscosity determination.

This is comprehended by the fact that the proposed viscometer is equipped with an additional adder with two predisposition devices, one of which is installed at the output of the temperature sensor amplifier and connected to

the positive chamber of the additional adder covered by positive feedback and the second is connected to the negative camera of the additional adder, the output of which is connected to the positive camera of the first adder and input 1 of the second anticipation device, each of the preliminary devices containing a membrane amplifier, an adjustable choke and capacitance.

The drawing shows a block diagram of the proposed device.

The device comprises a viscosity sensor 1, a viscosity amplifier 2, a logarithm 3, an adder 4, a temperature sensor 5, a temperature amplifier, devices 7-and 8 of a precursor, an adder 9 of a perturbation channel, a secondary device 1O,

The principle of the device is that when 1k} changes: Viscosity is liquid. bones trigger sensor 1, in silica 2, logarithm 3, adder4 and secondary PCB 10, when the temperature of the liquid changes, sensor 5, amplifier 6, devices 7, 8 and adder 9 operate.

The signal from the output of the adder 9 enters the adder 4. The ratio between the signals of the logarithm 3 and the adder 9 supplied to the adder 4 is maintained as the temperature changes. This is how temperature compensation is performed in statics.

To increase the accuracy of thermal compensation, it is necessary to maintain the ratio of the dynamic characteristics of the main signal line, i.e. viscosity lines (sensor 1 amplifier 29 log-exchange 3, adder 4) and disturbance lines, i.e. Line temperature (sensor 5, amplifier b). To do this, devices 7, 8 and adder 9 are installed on the temperature line, which together constitute the compensator.

Devices 7 and 8 are prefixed.

membrane amplifier, adjustable throttle and capacitance.

 The perturbation adder 9 consists of a five-membrane relay with rigid feedback and an amplifier with a gain factor K: 1.

To the input of the precursor device 7, blunt from the temperature sensor 5 through the amplifier 6, the signal of the current value of the disturbing action is the input parameter of the compensator of the perturbations. An intermediate signal from the output of the adder 9 is fed to the input of the second pre-device. The input signal of devices 7 and 8 is summed algebraically in the adder 9. The signal from the adder's output multiplied by the coefficient K 1 of the amplifying device enters the adder 4 of the viscosity line.

Claims (3)

Invention Formula A viscometer containing a viscosity sensor, the output of which is connected via an amplifier and a logarithm to a minus chamber of a summator, a temperature sensor whose output is via an amplifier connected to a plus chamber of an adder, and a secondary device connected to an output of an accumulator, characterized in that viscosity, it is equipped with an additional adder with two devices of anticipation, one of which is installed at the output of the temperature sensor amplifier EN is connected to the positive chamber ra covered by the positive feedback and the second is connected with the negative chamber dopolnitel'nog adder whose output is connected with the positive chamber of the first adder and to the input of the second device prenex, each of. Preliminary devices contain a membrane amplifier, an adjustable choke and capacitance. Sources of information taken into account in the examination 1. US Patent No. 3479863, cl. 73-5 1. 2.Patent of France No. 543О94 cl. & 01 N, 1967. 3. USSR author's certificate No. 266347, cl. G 01 N 11/00, 1968.