One of the most important standards that the API has set is the method used for measuring the density of petroleum. This standard is called the API gravity. Specific gravity is a ratio of the density of one substance to the density of a reference substance, usually water.
The most common symptoms of RSI include: 1  Pain. 2  Tingling. 3  A feeling of restlessness in the joint. 4  Weakness. 5  Throbbing. 6  Stiffness or cramp.
According to NINDS, the list of symptoms associated with RSD includes: 1  burning pain. 2  increased skin sensitivity. 3  skin temperature changes (warmer or cooler than opposing extremity)  skin color changes (blotchy, purple, pale, 1  red) skin texture changes (shiny, thin, sweaty)  changes in nail and hair growth patterns.