Specific gravity can be calculated using a test tube, or with known measurements.
Specific gravity is a measurement of one object's density versus a constant. In most cases, the constant is water. According to the Utah Geological Survey, specific gravity can also be used to help identify minerals. It is also an important part of the brewing process, because it gives a brewer the ability to know how much sugar has been absorbed into the water base. Calculating specific gravity is relatively easy with sufficient data, and unit conversions add only one extra step.
Instructions
Density Formula
1. Gather all your data. You will need the mass of the object and the volume it occupies. These units are normally represented in in kilograms (kg) and meters cubed (m^3), respectively.
2. Use the formula p = m / V, where p = the density, m = the mass, and V = the volume, to determine the object's density. The answer, or p, should be expressed in kg/m^3.
3. Find the ratio of the density of the object to the density of water. Use the equation SG = p/pH2O, where SG is the Specific Gravity, p is the density of the object, and pH2O is the density of water. The commonly used density of water is 1,000 kg/m^3, or the density of water at 39 degrees Fahrenheit or 4 degrees Celsius.
Converting
4. Convert the density of water from 1,000 kg/m^3 into g/l. This will enable you to complete the preceding calculation with the measurements you have in g/l.
5. Change kilograms into grams. 1 kg is equal to 1,000 g, so 1,000 x 1,000 = 1,000,000, or 1,000,000g/m^3.
6. Convert meters cubed in liters. 1 m^3 is equal to 1,000 l. 1 x 1,000 = 1,000 liters.
7. Simplify your answer. 1,000,000 g / 1,000 l = 1,000g/l. Working in grams per liter will return the same numerical result as working with kg/m^3.
Tags: density water, object density, density object, meters cubed
