Scope and description
This method mainly uses the Zahn Viscosity Cup (Zahn Viscosity Cup), also known as the Zahn Viscosity Cup, which can quickly and conveniently measure the viscosity of the coating in the laboratory and construction site. The characteristic of Zion Cup is that it can be immersed in the test liquid, no matter the liquid is hot or cold, so it is also widely used in the coating construction site or workshop. The time from the moment the cup is taken out to the interruption of the filament flowing out of the cup is the viscosity of the liquid, expressed in Zahn No# seconds.
2. Instruments and Materials
(1) Zion Viscosity Cup: volume (44±1) mL, see Figure 1; (2) Thermometer: range is 0~50°C, graduation is 0~50°C; (3) stopwatch: graduation is 0.2s.
3. Measurement method
(1) First, fully stir the liquid to be tested, and measure its temperature.
(2) Hook the small ring on the handle of the Viscosity Cup with your fingers, and immerse the cup body in the liquid for 1 to 5 minutes to achieve thermal equilibrium.
(3) Then quickly and steadily pull the Viscosity Cup out of the liquid vertically, and when the upper edge of the cup body comes out of the liquid surface, time it immediately.
(4) When the liquid flows out, the distance between the Viscosity Cup and the liquid surface should not exceed 150mm. Stop timing when the first break point occurs in the steady stream flowing from the small hole in the bottom of the cup.
4. Result representation
The test results are expressed in terms of liquid outflow time (seconds), and the difference between the two measured values should be less than 5% of the average value.
5. Instrument Description
(1) Zion Viscosity Cup is a bullet-shaped, corrosion-resistant, solvent-resistant stainless steel cup with an accurate small hole in the bottom of the cup. The Viscosity Cup is composed of 5 cups with different apertures. The volume of the cups is 44mL, and the measurement range is from 5 to 1800mm²/S. The technical parameters are shown in Table 1.
Cup No. | Outflow hole diameter/mm | Viscosity measurement range/(mm²/s) | Fluid materials suitable for testing |
1 2 3 4 5 | 2.0 2.7 3.8 4.3 5.3 | 5~60 20~250 100~800 200~1200 400~1800 | Oil or other liquid materials with low viscosity Oil, varnish, spray paint, enamel, etc. Medium-viscosity paints and inks Viscous paint, ink Very viscous mixture, screen printing ink |
(2) The Zion Viscosity Cup is an outflow viscometer, so the measured seconds can be converted into kinematic viscosity, and the calculation is as follows: v = k(t — c)
In the formula, v——kinematic viscosity, mm²/s;
t——outflow time, s;
k, c - corresponding constants (Table 2)
Table 2 Constants used in the viscosity formula
cup number | 1 | 2 | 3 | 4 | 5 |
k c | 1.1 29 | 3.5 14 | 11.7 7.5 | 14.8 5 | twenty three 0 |
6. Reference standard
American ASTM D 4212 "Determination of Viscosity by Immersion Viscosity Cup"
