Avoid These Highly Acidic Foods. 1  All meats such as pork, fish, seafood and poultry. 2  Dairy and eggs. 3  Grains and some legumes. 4  Artificial sweeteners, alcohol products, sugar, carbonated soft drinks. 5  Cigarettes and tobacco, coffee, black tea.
In more general terms specific gravity is the ratio of the density of a material to that of any standard substance, although usually this is water at 4 degrees Celsius or 39.2 degrees Fahrenheit. By definition, water has a density of 1 kg per litre at this temperature. The specific gravities of gases usually are compared to dry air which generally has a density of 1.29 g per litre. The specific gravity of all other materials is compared to water as a fraction heavier lighter or heavier density.
To convert from specific gravity to API, divide 141.5 by the specific gravity, then subtract 131.5. The specific gravity that should be used is that from oil at sixty degrees Fahrenheit. The 141.5 comes from the old Baum? scale the United States used as a standard of measure for any liquid with a density less than water.