SU1260754A1 - Device for determining surface tension of liquid - Google Patents

Abstract

The invention relates to the field of measurement technology and can be used to control the processes of preparation of solutions of surfactants. The purpose of the invention is to improve the performance and accuracy of measurements of the surface tension of the liquid by the method of maximum pressure in a gas bubble. The device contains a tank with a calibrated tube embedded in it. The tank is connected to a manometric vessel, which simultaneously serves as a receiver, with two overlapping tubes, one of which is located above the liquid level and the other below. The presence of two overlapping tubes between the manometric vessel and the pesyjpByapoM with a calibrated tube allows the hydrostatic pressure of the measured liquid itself at different levels in the manometric vessel and in the tank with the calibrated tube to be used to create the necessary differential gas. 1 il. Q S (L Ivd Od O "ch1

Description

The present invention relates to a technique for measuring the physicochemical characteristics of liquids, and, more specifically, to devices for the discharge of surface tension by the method of maximum pressure in a bubble.

The purpose of the invention is to improve the performance and accuracy of measurements by reducing the time to establish equilibrium and to ensure the possibility of measurements in stationary conditions.

The drawing shows a diagram of the proposed device.

A device for determining the surface tension of a fluid contains a reservoir 1 with a calibrated tube 2 located therein, connected to a pressure vessel 3, which simultaneously serves as a receiver and filled with the test liquid and an inert gas through process 4, the pressure measurement vessel 3 is connected to a reservoir 1 by a pipe 5 seconds valve 6, located above the end of the calibrated tube and the liquid level, and tube 7 with the valve 8, located below the tube end and the liquid level. The entire device is installed in the thermostat 9.

The device works as follows.

After the device is filled with the test liquid and inert gas, with valves 6 and 8 open, the liquid in the manometric vessel 3 and the reservoir. voire 1 is set at the same level. To prepare the device for measurements, it is necessary, having tilted it, to transfer part of the liquid from the manometric vessel 3 to reservoir 1, close valve 8, return the device to its original position and close i valve 6, To perform the measurements, you must open valve 8, Hydrostatic pressure of the liquid The gas at different levels in vessels 1 and 3 will provide a gas pressure drop in them, which is necessary for the formation and detachment of gas bubbles at the cut of the calibrated tube. At the same time, the liquid level in the pressure vessel 3 will increase, and in the reservoir - lower. The formation and separation of gas bubbles will cease when the hydrostatic pressure of the liquid is equal to the maximum gas pressure in the bubble.

Pg (H + h) + pgh,

where g is the acceleration of free fall;

neither;

H is the height of the liquid in the manometric vessel 3 relative to

cut calibrated tube; h is the height of the liquid level in reservoir 1 relative to the cut of the calibrated tube; p is the density of the test liquid; . d. - effective hole radius

calibrated tube; S is the surface tension coefficient.

In this case, the change in fluid levels will cease and the readings will be counted in statics. The distance H between the section of the calibrated tube and the meniscus of the liquid in the manometric vessel shall be counted.

The surface tension of the fluid is calculated by the formula

thirty

6 r fglic

To measure the surface tension of a fluid at temperatures other than room temperature, the operations of preparing for measurements and measurements are carried out under the conditions of thermostatting at the required temperatures using a thermostat 9

Claims (1)

Invention Formula A device dp for determining the surface tension of a fluid containing a reservoir with a built-in a negro calibrated tube and a manometer vessel connected to the tank and a calibrated tube, characterized in that, in order to increase the performance and measurement accuracy, a soya reservoir, is dinane with a manometric vessel with two overlapping tubes, one of which is located at the end of the calibrated tube in the reservoir, and friend - below its butt.