Convert from as, ass [Northern Europe] to cental

Unit Definition (as, ass [Northern Europe])
The as, ass [Northern Europe] is a traditional unit of mass for gold and silver, used in most of northern Europe but not in England. The unit varied in size from about 48 to 58 milligrams (0.75 to 0.90 English grain).

Unit Definition (cental)
The cental is an alternate name in Britain for the U.S. hundredweight, which is equal to exactly 100 pounds (the British hundredweight is 112 pounds). Introduced by British merchants around 1850, the name was apparently coined after the model of the quintal. The cental has sometimes been confused with the centner.