How to choose a table interface tensiometer

We generally call the tension between the liquid phase and the gas phase as surface tension. For example, we say that the surface tension of water at 20 ° C is 72.75, which means the surface tension at the interface between water and air. We also refer to the liquid-liquid tension as the interfacial tension.

Fully automatic tensiometer is a simple and easy testing instrument that uses physical methods instead of chemical methods. It can quickly and accurately measure the surface / interface tension values ​​of various liquids. It is not only a necessary instrument for scientific research and teaching, but also used in most production industries. The main measurement methods are platinum plate method, platinum ring method, rotating drop method, hanging drop method, and bubble pressure method. The following describes their corresponding instrument models, application scope and application direction.

The main application areas are: indoor research and on-site monitoring of tertiary oil recovery (chemical flooding); research on surfactants, detergents, emulsions and foams; research on fuel oils, lubricants, paints, inks and coatings; paper products, photosensitive Research on materials, pesticides, etc.

1. JK99 series automatic tension meter (compatible with platinum plate method and platinum ring method):

Platinum plate method: When the sensor is immersed in the liquid to be tested, the platinum plate will be affected by surface tension. The surface tension of the liquid will pull the platinum plate down as much as possible. When the surface tension of the liquid and other related forces and balance force reach equilibrium, the sensing platinum plate will stop immersing into the liquid. At this time, the balance sensor of the instrument will measure the immersion depth and convert it into the surface tension value of the liquid.

Platinum ring method: Because it is widely used in du Nouy surface tensiometer, this method is also called du Nouy method, and it is widely used because of its simple operation. The platinum ring method is called because a ring is formed between the test part and the liquid sample.

The JK99 series automatic tension meter adopts imported sensors. Although the cost is much higher than that of the domestic torque wire sensor, it ensures the measurement accuracy. At the same time, it adopts dual temperature control technology, with built-in electric temperature control heating or external bath temperature control to choose from.

The JK99C automatic tension meter is mainly used to measure conventional table / interface tension, because of its easy operation (one-button automatic), fast measurement speed (3 seconds), good repeatability, high measurement accuracy, etc., it is currently the most widely used Tensiometer. The disadvantage is that it can not measure ultra-low interfacial tension (such as the interfacial tension between oil displacement agent and crude oil should be 10-5mN / m, which cannot be measured with JK99 series).

The JK99B type must be connected to a computer before it can be used. The JK99C type is an integrated dual-use machine with a built-in LCD digital display and a small printer. It can be operated independently by a single machine, or it can be connected to a computer to observe the dynamic change of the tension curve. The accuracy and other parameters of the two models are exactly the same.

JK99D automatic tensiometer is a newly upgraded product designed and produced recently. It integrates the functions of B and C models, redesigns the constant temperature water bath cover and electric heating platform, increases the magnetic stirring function, and increases the optional CMC Suite

2 JJ2000B Series Rotary Drop Full Range Meter / Interface Tensiometer (using rotary drop method)

Rotating drop method: The basic principle of the rotating drop method is to obtain the interfacial tension from the shape and size of the drop according to the Bashforth-Adams equation, and the drop is placed in a certain centrifugal force field by rotation, and the balance shape of the drop can be changed by adjusting the rotation speed. For determination. Mainly measures ultra-low interfacial tension.

The JJ2000B series is mainly used to measure ultra-low interfacial tension, especially in the petroleum industry (for example, the tertiary oil recovery in the petroleum industry requires measuring the interfacial tension between the displacing agent and crude oil). It is worth noting that although this series is a full-range tensiometer, due to its method and instrument characteristics, it is not as convenient, economical, and accurate as the JK99 series when measuring conventional table / interface tension.

JJ2000B Series Rotary Drop Full Range Meter / Interface Tensiometer adopts advanced continuous zoom optical system and Nissan CCD camera, digital images are transferred to the computer, and the continuous zoom can be adjusted from 55-315 pixels per millimeter. The computer directly sets the working temperature (electrically controlled temperature) and speed, and the video optical system collects the image and measures it on the computer. High-speed synchronous motor drive, speed range 1000-10000r / min, control accuracy: 0.1%. LED cold light source, long service life, no heat.

JJ2000B2 type rotating drop interfacial tension / static drop contact angle measuring instrument (dual-purpose type) can be used to measure the contact angle of liquid to solid, that is, the wettability of liquid to solid. Liquid / liquid interfacial tension. The instrument consists of two independent parts, sharing an optical video system.

3 JC2000 series static drop contact angle / interface tension measuring instrument (using hanging drop method)

Hanging drop method: The surface tension is calculated by processing the largest droplet image. JC2000 series static drop contact angle / interface tension measuring instrument is mainly used to measure liquid-solid contact angle and solid surface energy, but it also comes with a hanging drop method measurement table / Interface tension function. The hanging drop method for measuring surface tension is classic, intuitive in image, and reliable in data. However, it has high requirements for the operator and the test tension is not as fast as the JK99 series. It can be used for scientific research and teaching and is not suitable for batch test data on the production line.

4 JBT07A automatic bubble tension measuring instrument (using bubble pressure method)

Put the liquid to be measured into a constant temperature sample container. A capillary made of glass or polytetrafluoroethylene will be immersed in the liquid at a given immersion depth. During the test, gas or inert gas passes through the capillary tube, forming bubbles at the end of the capillary tube, and measuring the pressure of the bubble.
When the bubble pressure tensiometer JBT07 continuously increases the rheological rate of the gas, the frequency of bubble formation increases, and the survival time of each bubble decreases accordingly. The bubble speed and frequency were set during the experiment. When the radius of the bubble at the end of the capillary is equal to the radius of the capillary, the bubble pressure reaches the maximum value. Once the bubble radius exceeds the capillary radius, the bubble pressure is significantly reduced. The maximum pressure for generating bubbles is proportional to the dynamic surface tension. The hydrostatic pressure P is proportional to the immersion depth of the capillary. For example, the environmental department can use the equipment to effectively detect changes in water quality of natural water bodies and sewage discharge sources of industrial and mining enterprises.