Welcome To Whitehall Township Whitehall Township is located in the center of the Lehigh Valley. The Township is one hour north of Philadelphia and an hour and half from New York City.
SALINITY OVERVIEW Salinity is the concentration of dissolved salts in water, usually expressed in parts per thousand (ppt). Objects float higher in salt water than fresh water because salt water is denser (heavier per unit of volume).
What is a PPD? PPD stands for purified protein derivative, which is the solution used for the test. Alternative names you may hear the test called are tuberculin skin test, TB test and Mantoux test. During the procedure, a small amount of the solution is injected with a needle, right under the skin of the inner forearm.