How to measure viscosity using Elcometer Flow Cups

 

When measuring the viscosity of a liquid, it is a common misconception that you are measuring how thick or thin a liquid is. What you are really measuring is the resistance a fluid has to flow.

 

The viscosities of paints, varnishes, and oils for example; can be typically measured as part of a series of tests to ensure they are fit for purpose.

 

There are a number of ways to measure the viscosity of a liquid, one of which is flow cups.

 

A flow cup is a cup of a specified size and volume, with an overflow channel at the top, and a hole of a defined size in the bottom. And they are available in a range of designs in accordance with National and International Standards, with various orifice diameters to suit different viscosities.

 

To test, you will need a flow cup, a flow cup stand, a glass plate and bubble level, a stopwatch, a thermometer with a liquid probe, and a container of your sample liquid - ensuring there is enough of a sample to more than fill the flow cup.

 

Well, if a preferred flow cup isn’t listed on the technical data sheet of the liquid you are testing, then typically you should select a cup that will give an estimated flow time of between 30 and 100 seconds. However this is dependent on the range of the flow cup you are testing with, or the test method or standard you are working to.