Comparison of NDJ Viscosity and Brookfield Viscosity
NDJ and Brookfield viscosity measurements are both reliable indicators of fluid flow ability. However, they measure different properties in slightly different ways.
NDJ viscometers measure the time it takes for a specified volume of liquid to pass through an orifice under a set pressure. For NDJ measurements, the pressure is constant, but other parameters (like temperature and the size of the orifice) can affect results.
NDJ viscometer is a rotational viscometer that measures the torque required to rotate a spindle in a sample fluid. The device uses a simple, low-cost design that is popular in China and other parts of Asia. It is suitable for measuring low-to-medium viscosity samples, such as paints, inks, and adhesives. The NDJ viscometer measures viscosity in cP or mPa.s units, depending on the model.
Brookfield viscometers measure torque resistance as it passes through a spindle immersed in liquid. The torque is measured at multiple different speeds and used to construct a graph showing the fluid’s viscous behavior over time. Unlike NDJ viscometers, temperature, and spindle size are not factors in Brookfield viscometer readings.
Brookfield viscometers are also rotational viscometers but use more advanced technology than NDJ viscometers. Brookfield devices measure viscosity by rotating a spindle in a sample fluid and measuring the torque required to make the spindle rotate. The device uses a digital display unit to provide readings in cP or mPa.s units. Brookfield viscometers can measure a broader range of viscosities, from liquid to highly viscous fluids, such as pastes, creams, and gels.
Comparison between NDJ and Brookfield viscometers:
The primary differences between NDJ and Brookfield viscometers are sensitivity, testing range, and accuracy. Brookfield viscometers are more sensitive, especially for high-viscosity samples, and can measure viscosity more accurately than NDJ viscometers. However, NDJ viscometers are more affordable and suitable for low- to medium-viscosity fluids, which is why they are popular in Asia.
Overall, NDJ viscosity measures are more stable over time and easier to quantify than those of a Brookfield viscometer due to the consistent pressure used in testing. However, since torque-based readings can provide more detailed results, Brookfield viscosity measures can be useful for a more in-depth analysis of a fluid’s behavior. In the end, both methods are reliable and provide necessary insight into the properties of a given fluid.
No single method is perfect, so it is important to understand the benefits and drawbacks of each before deciding which one to use. Ultimately, the most effective decision depends on the type of fluid being tested and the desired end result.
In conclusion, NDJ viscosity and Brookfield viscosity are both reliable ways to measure how easily a fluid flows. Each method has its own advantages and disadvantages, so it is important to understand these differences before selecting which one to use. Both measurements can be used separately or together to gain a deeper understanding of fluid properties. With the right knowledge, both methods can be applied effectively and efficiently.
As a reference, below is a viscosity by NDJ and brookfiled viscometers comparison chart of mikazone HPMC/HEMC to assist readers in understanding how different viscometers compare.
Viscosity ( NDJ,2%.20℃)
Joint Filler / Tile Grouts
Gypsum or Cement-based Plaster / Rendering / Joint Filler
Gypsum-based plaster / Skim Coat / Wall putty
Plaster / Skim Coat / Wall putty / Tile adhesive
Gypsum or Cement-based products / EIFS / Tile adhesive
Tile adhesives / EIFS / EPS Panels