What is involved here are two different standards. The ISO No. 4 cup is based on the standard ISO 2431. It is designed for paints and other related products with a viscosity range of 34-135cSt. The diameter of the filter tip is 4mm. Viscosity cups with a flow time of 30-100 seconds.
The Tu 4 Cup is designed according to the standard GB/T 1723-93, and is suitable for measuring the conditional viscosity of paint and other related products (the outflow time is not more than 150 seconds, and the diameter of the filter tip is 4mm). Under certain temperature conditions, measure the time for the quantitative sample to completely flow out from the hole of the specified diameter.
Specific difference diagram
| standard | Filter Diameter (MM) | Flow time (seconds) | Viscosity range (cSt) | |
| ISO 4 Cup | ISO 2431 | 4 | 30-100 | 34-135 |
| 4 cups of coating | GB/T1723-93 | 4±0.02 | not more than 150 | 30-100 |
