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).
It means Parts Per Million. It is generally used to measure and denote the concentration of chemical in very low quantity. e.g we say the sea water contains 0.5 ppm of pure gold. Or human blood contains 20 ppm of iron oxide. This unit is used when other units like % and fractions are too big to denote the quantity.