A & D Viscometers and liquid viscosity measurement provided by A&D

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Viscometers
SV10/100 SERIES

Measuring viscosity is an effective way to know the state (properties of matter) or fluidity of a liquid or gas. It plays an important role in the quality control and in various research and development stages of a wide range of industries, including Food, Chemical, Pharmaceutical, Petrochemical, Cosmetics, Paint, Ink, Coatings, Oil and Automotives. For example, the viscosity of a liquid is an important parameter for designing the piping in a plant or transporting crude oil or chemical agent through a pipeline. In the electronic engineering industry, photresist fluid is used in the production processes of the printed circuit board, cathode-ray tube, and flat liquid crystal display. Controlling the viscosity of photoresist fluid is a crucial factor to determine the qualities, performance, and yields of finished products. Among those industries, it has been also recognized that controlling optimum viscosity reduces production costs.

Brochure (pdf file)

Viscosity, which is also called a viscosity coefficient, is a measure of a fluid’s resistance to flow. It is the substance constant indicating the magnitude of the fluidity of a fluid. In general, viscosity is associated only with liquid. Gas also has viscidity, but it is a relatively inviscid fluid, the resistance to flow can be ignored.

A&D’s Sine-wave Vibro Viscometer SV Series is designed for sensitive viscosity measurement. The SV Series provides a wide dynamic range and high resolution by vibrating with a frequency of about 30 Hz, which is equivalent to the resonance of the detection system. As a result, the SV-10 handles the dynamic range from 0.3 mPa•s to 10,000 mPa•s, and can continuously measure in the measurement range with repeatability, accuracy, and stability. This wide dynamic range enables it to measure viscosity changes in processes of thixotropy liquid during its turning from sol (colloidal solution) into gel, or in such processes as curing resin, adhesive, or paint, which conventional rotational viscometers cannot continuously measure.

A&D’s Vibro Viscometer has a unit to detect viscosity of a sample, which is composed of two thin sensor plates that vibrate. It drives the sensor plates to vibrate at uniform sine-wave vibration in reverse phase, like a tuning fork. The SV Series comes equipped with the WinCT-Viscosity, Windows Communication Tools Software. With WinCT-Viscosity, you can create real time graphs of data on viscosity and temperature. In addition, the scaling function is available and the logarithm display is selectable in the function. Saving the measurement data by "CSV" file and opening it with WinCT-Viscosity is very easy and convenient for analyzing sample fluid viscosity.

WinCT Viscosity
Via an RS232C interface, the WinCT-Viscometer software lets A&D's SV series Sine-wave Vibro Viscometer display measurement progress in real time on a PC, and easily transmit the measured results to save or analyze. The WinCT-Viscometer CD-ROM is a standard accessory with the SV Series viscometer.

Example of Measurement Display Using RsVisco

(1) Example of RsVisco Display
RsVisco software reads the measured results (CSV file) and creates a graph representing the measuring viscosity in real-time, as shown in the figures below. Figures 1 and 2 show the graphs representing viscosity changes of silicon oil (a Newtonian fluid) measured at room temperature while leaving it cooling down from about 45°C to 25°C. Figure 1 shows the elapsed time plotted along the x-axis, with the viscosity (left) and temperature (right) plotted along the y-axis. Figure 2 presents the same data by plotting the temperature along the x-axis and the viscosity along the y-axis. These graphs ideally present the linearity of the correlation between changes in viscosity in response to changes in temperature.

Figure 2. Correlation Between Viscosity Change in Response to Temperature
Change in Silicon Oil.

(2) Example of Viscosity Measurement of Water-Based Paint
Figure 3 shows a graph representing the measured result of a water-based varnish at room temperature under fixed conditions. This sample shows a stable viscosity despite the elapsed time.

Figure 4 shows the measured result of a water-based paint (black)
at room temperature under fixed conditions.

After starting the measurement, this sample shows a tendency of gradually decreasing (thixotropy). To evaluate the viscosity of a sample such as this one, experimentally find the time when the decreasing tendency becomes slow. We can evaluate the viscosity value from the time.

Figure 3. Example of Viscosity Measurement of Water-based Varnish

Figure 4. Example of Viscosity Measurement of Water-based Paint (Black)

(3) Viscosity Measurement of Food
Figures 5 and 6 are graphs representing the measured results of the viscosity of egg white while heating it with a heater from room temperature to about 80°C. This clearly measures the behavior of egg white rapidly coagulating over 60°C. The graphs precisely show the properties of protein (albumin), which is the
main component of egg white.

Figure 5. Example of Viscosity Measurement of Egg White

Figure 6. Increasing the Process of Viscosity of Egg White with Temperature Increase

Figures 7 and 8 are graphs representing the measured results of the viscosity of egg white (shown in Figures 5 and 6), illustrated with logarithmic scale on the y-axes (viscosity). Figure 8 in particular shows that when the temperature was below 60°C, the viscosity of egg white decreased as the temperature increased, like a common liquid does. Once it surpassed 60°C, however, the viscosity increased rapidly as its protein coagulated. The SV Series viscometer can capture precise dynamic changes in viscosity as well as small changes peculiar to a sample.

As demonstrated below, WinCT-Viscosity (RsVisco) can indicate a logarithmic axis on the viscosity axis to clearly present the changes in viscosity of a wide range, or of non-linearity.

Figure 9 shows an example of gelatin solutions with viscosity measurements of 2.5% (green line) and 5% (red line) while varying the temperatures. The temperature is plotted along the x-axis, and the viscosity along the y-axis. The figure shows that the coagulation point depends on the concentration of the solution.

Figure 11 shows the measured result of Worcester sauce under fixed conditions (room temperature).The SV-10 measurement indicates that Worcester sauce shows a stable
viscosity in response to the elapsed time.

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