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.
Symptoms of Chronic UTI. Symptoms of a UTI that is affecting your bladder include: 1  frequent urination. 2  bloody or dark urine. 3  burning sensation while urinating. 4  pain in your kidneys (in your lower back or below the ribs). 5  If the UTI spreads to your kidneys, it might cause: 6  nausea and vomiting. 7  chills.8  fever.ymptoms of a UTI that is affecting your bladder include: 1  frequent urination. 2  bloody or dark urine. 3  burning sensation while urinating. 4  pain in your kidneys (in your lower back or below the ribs). 5  If the UTI spreads to your kidneys, it might cause: