These cans can be purchased through most lab suppliers. Measuring cylinders can be used instead of these cans to achieve the same effect.
The can is filled as high as possible with water and an object inserted slowly into it. As the object fits into the can, the water it displaces pours out of the spout. This displaced water can then be measured and will be the same as the volume of the object. For example a 10 cm³ cube will displace 10cm³ of water.
The density of some common objects are listed below for comparison:
The density of a material can be worked out using this equation:
where p is the density of a material, m is mass and V the volume.
With the density can and an accurate balance, we can work out the volume of a substance and also the mass. From this we can, using the above equation, work out the density of the substance.