A&D’s Solution for Quick and Repeatable Low Viscosity Measurements Continues to Evolve

TOSHIMA-KU, Japan - Jan. 8, 2015 - PRLog -- A&D Company, Limited, a multinational manufacturer of measuring equipment for laboratory and industrial use, is proud to announce the international launch of their flagship tuning fork vibro rheometer: the RV-10000A.

About a year ago, its predecessor, the RV-10000, was introduced as a breakthrough alternative to conventional methods in the research of non-Newtonian fluid properties. Drawing on A&D’s proven sensor technology for high-resolution analytical balances, it provided quick stability and high repeatability with low viscosity fluids (e.g. below 100, 10 or even 1 mPa.s), which were not possible with other types of rheometers, such as rotational ones.

As a brief description, in the tuning fork vibro method two thin sensor plates in a tuning fork arrangement are vibrated with electromagnetic force at their natural (resonant) frequency of 30 Hz within the sample fluid. Viscosity is then calculated based on the amount of electric current required to drive and maintain the sensor plates at a constant vibration amplitude.

How the shear rate is changed

With the RV-10000, it was possible to change the shear rate by altering its sensor plate amplitude while keeping the frequency at 30 Hz, which results in differing vibration speeds. However, there was some inconvenience to users in that the amplitude was only alterable to eight levels (0.07 / 0.1 / 0.2 / 0.4 / 0.6 / 0.8 / 1.0 / 1.2 mm peak-to-peak) by manually pressing a key. Also, changes in amplitude could not be converted to actual shear rate values, or used as an axis variable when creating graphs using the provided software, allowing users only crude measurements and data analyses.

The new RV-10000A has no such limitations thanks to its dedicated controller with 7-inch color touch-panel LCD display. Specifically, the controller can automatically and more finely change the amplitude and capture data in a manner as programmed by the user. It also converts each amplitude into a numerical shear rate based on the required electromagnetic force (i.e. shear stress) and obtained viscosity value. Further, it graphs measured values in real time so that viscosity changes as a function of time, temperature, and/or shear rate become plainly visible.

Unique advantages of the RV-10000A

Of course, one shouldn’t forget the unique strengths of the tuning fork vibro method, on top of the new features of the RV-10000A above. To quickly reiterate them, firstly, it can uninterruptedly measure from very low to high viscosity (max. range 0.3 to 25,000 mPa.s) with a single viscosity detection system. It also achieves repeatability as high as 1% of the measured value (by standard deviation) for its entire measurement range.

Secondly, it has a temperature sensor (0 to 160 ºC range) located near the viscosity sensor. By using the provided water jacket with any standard separately purchased temperature control tank, users can control the sample fluid temperature (between 0 and 100 ºC) in order to measure the viscosity at a constant temperature or see how the viscosity varies with temperature.

Thirdly, the two sensor plates vibrating in opposite directions allow measurement of the sample fluid even while it is flowing or being stirred. At the same time, the vibration itself causes only minute displacement in the sample fluid and keeps changes to its temperature and physical structure to a minimum.

Fourthly, compared with conventional methods, users can set the sample fluid, start measurement and obtain the viscosity value in a much shorter time (the RV-10000A requires only 20 seconds to stabilize). Cleaning after measurement is also very easy.

Finally, both one-point and two-point calibrations are possible by users themselves using either viscosity standards or fluids of known viscosities. In addition, for a viscosity range around 1 mPa.s, a highly useful, “simplified calibration function” is available, which uses water and requires a simple one-key operation for quick and automatic calibration.

Fields where the RV-10000A will be especially useful

With the RV-10000A, a whole new vista of materials research and development is opened wide, in particular for those who have been struggling to obtain stable results with low viscosity fluids. It is unmatched in its ability to measure a diverse array of samples, such as chemicals, paints, adhesives, coating materials, cosmetics, foods, soils, and so on.

Thanks to its extremely high sensitivity, measured values are such that they can accurately represent humans’ actual sensations. It is therefore possible, for example, to study how a hand cream will be felt when smoothed over the skin, or how pleasantly a drink will go down the throat, with hitherto unachievable precision.

Since its sensor plates exert little interference to the sample, the RV-10000A enables the measurement of fluids such as foams (e.g. whipped cream) without breaking their tiny air bubbles or dispersion systems (e.g. colloidal solutions) while they are settling. Moreover, various kinds of slurry that would scrape the surface of the spindle of a rotational rheometer can also be measured without problems.

Besides use in R&D, the quick stability and high repeatability of the RV-10000A also make it a powerful tool for quality control in factories where test samples are taken from the production lines to a laboratory to make pass/fail judgments. To do so, inspectors may simply want to develop a tolerance around a known good sample as a reference and then just use the rheometer as a kind of Hi/Go/Lo comparator.

However, when the test samples are low in viscosity, conventional methods would typically produce rather inconsistent values, making reliable comparisons and judgments very difficult. Besides, they tend to take too long for each measurement, and keep the production lines waiting all that time. With the RV-10000A, the whole processes will be much more efficient and cost-effective.

For quality inspection purposes, what matters is often whether the value is the same or different from day to day or batch to batch, and the value as such is usually not so important. Therefore, even materials whose viscous resistance was previously difficult to quantify, such as powders, can also be taken as test samples.

Additional details, technical reports and application examples can be found on the A&D website at http://www.aandd.jp/.

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A&D Company, Limited, headquartered in Tokyo, take advantage of their world-class analog and digital signal processing technologies to produce a diverse array of laboratory and industrial measuring equipment. In particular, they are known as Japan’s top manufacturer of electronic weighing instruments ranging from ultrasensitive micro analytical balances to scales of several tons of capacity. Their innovations are always aimed at providing users with high practical utility and high value for the price. To find further information on A&D, visit http://www.aandd.jp/.