For a good Viscosity Cup, the general habit of domestic users (the editor has limited knowledge and little contact with foreign users) is: imported ones are good, reliable, and expensive! To be honest, this is indeed the current situation.
From the point of view of the entire Viscosity Cup manufacturing companies around the world, large and small factories, brands (whether they are self-produced or OEM), are marked to meet Ford, ASTM, ISO, GB and so on. But actual accuracy varies widely. Sometimes this can’t really be blamed on the manufacturer. Judging from the prices of hundreds of Viscosity Cups on the shelves of Beichao, the cheapest one is 130 RMB, and the most expensive one is more than 4K. For those who only want to buy cheap or expensive ones, Please detour, this article is not suitable for you, the price range is suitable for you. For users who are hesitant to buy expensive or cheap ones, you can listen to them in detail:
Viscosity cup is used as a measuring tool. A good Viscosity Cup should have high enough precision, which is good!
So what kind of precision Viscosity Cup is good? Generally speaking, the international immersion Viscosity Cups, Ford cups, and ISO Viscosity Cups are within ±2%, and some Zahn cups are within ±2~3%. Please note that the accuracy of international marking is very different from that of small non-standard domestic factories. You can label ±0.00001% if you want. However, foreign manufacturers of imported Viscosity Cups are very serious in this area, as much as they want. So sometimes it is not necessarily possible to see the difference between a 2,000 yuan cup and a 200 yuan cup through the parameters of the Viscosity Cup. I feel that the material is the same, the appearance is the same, how can there be a difference!
Hey, this is what the editor is going to talk about today! The difference is hundreds of thousands of miles !
The Viscosity Cup actually uses the principle of gravity to calculate the time for the fluid to flow out of the specified aperture. Imagine, under what circumstances will the cup be inaccurate? Will it tilt? Will there be an error in the size of the orifice? Will the inner wall of the cup deal with the obstruction of the fluid? Will the orifice aperture details be rough? Will it be affected by different volume shapes (for example, if one cup has a thick wall and needs to be taller in order to achieve the specified volume, while the other has a smaller wall thickness and should be relatively lower), will this affect it?
Let’s use an example to illustrate. The aperture is easy to understand, so I won’t talk about it. Let’s take the fixed rods at both ends of the portable Zahn cup and the aperture of the cup to talk about it in detail.
What happens if the orifice is not perfectly centered? Because the fluid flowing out due to gravity will "bend", this will greatly increase the time error of the outflow
Figure 1: Viscosity Cup Center Alignment
If the two ends of the cup arm cannot be accurately welded on the line of symmetry, the cup will not be able to rely on gravity to achieve balance when the cup is carried in the end. This kind of manual error can not be avoided, which will increase the error even more.
Figure 2: Alignment of Viscosity Cup handles
Drawing these 2 pictures has already taken up a lot of Xiaobian’s appointment time for the Qixi Festival, and there are many details that I haven’t had time to talk about, but one point needs to be emphasized. At present, imported cups have detailed error marks, and domestic ones are almost none, at least small. I have no impression. In addition, for the cups with relatively high prices, in addition to the cups, some of them have calibration certificates. This kind of cups have passed the traceable calibration when they leave the factory. What is the purpose of the inspection? After you figure out the purpose, you can choose what kind of Viscosity Cup to buy.
In the end, the editor has no intention of burying our Greater CHINA products. What’s more, I hope that we can produce some truly high-quality instruments with our heart while pursuing profits, because this kind of heart is more about the heart than the technical level. Can it be achieved. In CHINA, domestic brands such as Modern Environment and Pushen are at the forefront of the country. As for the dozens of yuan on a certain treasure, those are not for testing data, but just for testing. So, stop saying that things from the North and South Tide are expensive! It doesn't matter if I am wronged, the brand of NBCHAO can't be wronged!
