I do not know how scientists continue to purchase equipment that is very difficult to use, expensive and outdated. There is really no need for them when better instruments have replaced. That is the nature of science and technology isn't it? I do not see so many people using slide rule aka slipstick today. This device should have found its way to the land of obsolete a long time ago. So today I heard that the CSC Tensiomat 21 tensiometer that they have been making for decades is being discontinued.
So there is one less surface tension company that:
a) sells instruments with really expensive bendable rings
b) that frustrates students to use
c) gives confusing results that are not reproducible (partly because of a and lot to do with b)
I would rather use something that works like it was built for the 21st century.