




The ISO outFlow Cup is designed and manufactured according to the relevant provisions of the international standard ISO2431-1993 Determination of outflow time by outFlow Cup for paints and varnishes and the national standard GB/T6753.4-98 Determination of paint outflow time-ISO outFlow Cup method. This outFlow Cup is used to test the outflow time of Newtonian or near-Newtonian liquids.




1. Stopwatch: Accuracy 0.1 (self-provided)
2. OutFlow Cup holder (optional)
1. Before or after measurement, wipe the inner wall repeatedly with a gauze cloth dipped in the solution, twist it into a rope with soft paper, and pull it repeatedly at the outflow hole.
2. Put the outFlow Cup on the bracket and adjust the level of the bracket.
3. Prepare a stopwatch with an accuracy of 0.1 second, and hold the outflow hole with your hand at the same time.
4. Slowly pour the measured liquid with a controlled temperature (according to user requirements) into the outFlow Cup to avoid air bubbles. When the liquid exceeds the mouth of the cup, use a scraper or glass to scrape it flat.
5. Start the stopwatch and quickly release the finger holding the outflow hole, stop the stopwatch when the outflow of liquid is interrupted, and record the outflow time.
The measured outflow time is calculated according to the following formula for kinematic viscosity mm/s
| cup number | ISO-3 | ISO-4 | ISO-5 | ISO-6 |
| formula | V=0.443t-200/t | V=1.37t-200/t | V=3.28t-220/t | V=6.90t-570/t |
Where: v=mm²/s
t = outflow time
Cistok = K value × outflow time - (C ÷ outflow time)
Centipoise = centistok x specific gravity
Note: In order to obtain more accurate data, the outflow time can be measured several times and the average value can be calculated.