Two Factors That Change Viscosity

The same material does not always have a constant viscosity. We will introduce two factors that cause viscosity changes.

Viscosity dependent on temperature

Viscosity is very sensitive to temperature. The table below shows the change in viscosity of water, mercury, and glycerin depending on the temperature.

【Change in viscosity of water】

Temperature	Viscosity
0℃	0.018 dPa·s
20℃	0.010 dPa·s
100℃	0.0028 dPa·s

 【Change in viscosity of mercury】

Temperature	Viscosity
0℃	0.017 dPa·s
20℃	0.016 dPa·s
100℃	0.012 dPa·s

 【Change in viscosity of glycerin】

Temperature	Viscosity
0℃	121 dPa·s
20℃	15 dPa·s

Mercury does not change much, but water changes considerably with temperature, and glycerin changes much more than water. As an extreme example, there are some fluids whose viscosity increases several times if the temperature drops by 1°C. In order to stabilize the quality, always measure the temperature when measuring the viscosity.

Viscosity changes over time

Temperature is not the only factor that affects viscosity. Time is also closely related to viscosity.

Some fluids become less viscous when mixed, and return to their original viscosity after being left for a while. Such fluids are called thixotropic fluids. Conversely, some fluids become more viscous when mixed and return to their original state when left unattended. In addition, there are fluids (aged) that become less viscous when mixed and do not return to their original state.

A constant viscosity cannot be measured with such a special fluid, but since a viscometer is a viscosity direct reading type, it is possible to measure how the viscosity changes moment by moment.

RION's viscometer is recommended for measuring viscosity!

RION's viscometer is recommended for the following three reasons.

１．Confidence in accuracy

RION has a long history of manufacturing and developing viscometers. Utilizing our many years of knowledge and experience, we are able to achieve accurate viscosity measurements that are competitive with our competitors.

２．Portable type that can be measured anywhere

Most common viscometers are large and heavy. However, RION's VT-06 is compact and lightweight while maintaining measurement accuracy. The structure is simple, so even people with no knowledge or experience of viscosity measurement can easily measure it.

３．Loved by many customers around the world

RION is a Japanese manufacturer, but the viscometer VT-06 is used not only by customers in Japan but also by customers in countries around the world. VT-06 may be used for quality control in the things you usually use and eat.