The Water Scale is ingenious in its simplicity, using little more than a piston and a tube to weigh your cooking ingredients. The scale, from designers Muzaffer Kocer and Ayca Guven, uses Archimedes’ Principle to measure weight.
The bowl of the scale is connected to a plunger that floats on top of water inside the scale’s body. When the bowl is pushed down, the water is displaced and flows up a tube. This tube – which also contains a floating plastic ball to make it easier to see – is graduated. You read it just like a thermometer.
Archimedes’ Principle says that – for a floating object – the amount if water displaced is equal to the mass of that object. Thus a potato weighing half a kilo (a big potato, to be sure) and dropped into a floating bowl will shove aside half a kilo of water. Thus a scale can be calibrated.
This design keeps the Water Scale incredibly simple, as you can see from the rendered images above, requiring no electronic or complex mechanical parts. I have one question though. The scale is designed to weigh objects of up to a kilogram (2.2-pounds). Doesn’t this mean that you’d have to have a kilo (liter) of water on board to do that?