The shekel of the sanctuary was a standard unit of weight in use for precious metals. It is possible to identify this unit as the equivalent of eleven grams on account of ancient coins discovered in Israel. It can be observed here that one shekel was the equivalent of twenty gerahs
(see also Exodus 30:11–16).
47 you shall take five shekels per head; you shall take them according to the shekel of the sanctuary (the shekel of twenty gerahs),