the method used to determine oil volume in a stock or storage tank. A gauge table for the tank that relates oil height to oil volume is prepared by a process called strapping. The oil height is measured by either the innage or the outage method. The more common innage method is made by running a gauge tape with a guage bob on the end, into the tank at the reference point on the tank hatch or on the gauging platform through the oil to the strike plate on the tank bottom