There are reasons to make a DIY measuring cup. It is cheap. It saves the cost of buying inferior or high quality version. It is customizable – small, medium or big : ml, liter, quarts or pint : small or large graduation. Never worry about borrowers. Create, let go and create again. Making one is easy and it is as simple as conducting intermediate laboratory experiment.
1) Get the container to be transformed into a measuring cup. It could be an empty PET bottle, plastic drinking glass, plastic cup or any other container with transparent to semi-transparent appearance.
2) Provide a permanent marker. It should produce a thin, visible and permanent line. A knife or any pointed object capable of scratching the container surface will do.
3) Choose between two available tool for calibration.
a) Volumetric Glassware. Either graduated cylinder or volumetric flask. Class A volumetric flasks are very accurate and more accurate than graduated cylinders. Erlenmeyer flasks and beakers are not recommended. Their printed graduation are rough approximates.
b) Digital Weighing Scale. It can measure volume following the truth that one ml of pure water is equivalent to one gram.
4) Decide on graduation (1,2,3,4 ml: 5,10,15,25 ml: 10,20,30,40 liters) Judge the graduation base on purpose and container size. A one ml graduation is crazy on a six liters mineral PET bottle while a one liter graduation is impossible for a 300ml glass.
5) Place the container on flat and level surface. E.g. for 5 ml graduation, measure 5ml water using volumetric equipment or 5 g distilled water using digital weighing scale. Pour to container carefully. Find the lower meniscus of liquid and mark it. Repeat until the container is full.