2.4.1 Each cargo tank of a tanker that is connected
to a vapour collection system should be equipped with a cargo gauging
device which:
-
.1 provides a closed gauging arrangement that
does not require opening the tank to the atmosphere during cargo transfer;
-
.2 allows the operator to determine the liquid
level in the tank for the full range of liquid levels in the tank;
-
.3 indicates at the location where cargo transfer
is controlled, the liquid level in the tank; and
-
.4 if portable, is installed on the tank during
the entire transfer operation.