Displacement Scale

I have a project to do that involves moderately accurate weighing. A good kitchen scale would set me back $50. But what if I just used a measuring cup with really accurate markings to measure the displacement of water? Impractical for large projects, but as far as I know perfectly accurate for getting weight. Since every ml of water at 4C equals one gram to be displaced. Provided I carefully look at the meniscus I should be able to measure as little as 25 grams using a standard measuring cup with another container floating freely in it. And with some judicious estimation I might get to within a reasonable error of my goal weights.

What project you might well ask. I am making ink. I am using as near as I can replicate the ink prepared by boiling galls recipe that takes several hours of gently simmering the crushed galls in distilled water. A long task, but one made lighter by listening to a book while I do it.