Different architectural coatings have different viscosities and belong to different fluid forms (such as Newtonian fluid and non-Newtonian fluid). Not all architectural coatings can be used to measure viscosity by Flow Cup method. This method is not suitable for coatings with high viscosity (such as greater than 150 seconds) or strong thixotropy and no fluidity. A preliminary test can be performed to check that the sample is suitable for Flow Cups. First measure the outflow time according to the specified method of the Flow Cup. The time between filling the spout cup and releasing your finger should not exceed 5 seconds. Measure again, but this time. When measuring, the sample should stay in the Flow Cup for 60 seconds before releasing the finger.
If the difference between the two measured values is greater than 10% of the average value of the two times, the sample is not suitable for measuring the viscosity by the ISO Flow Cup method.
