Innage oil gauging tapes are graduated to take submersion readings that measure the actual depth of liquid remaining in a tank. They require lowering the blade from the top of the tank until the plumb bob touches the tank bottom or a reference plate in the tank. The blade is then retracted and read at the point where the tank contents wetted the blade. Innage tapes are commonly used to measure levels of gasoline, fuel oil, crude oil, and other petroleum products.

Outage oil gauging tapes are graduated to take surface readings that allow calculating the level of liquid in a tank based on the amount of liquid removed and the total tank depth. Also known as ullage tapes, they require lowering the blade from the top of the tank until the plumb bob reaches the top of the liquid. They are commonly used to measure thick liquids that could prevent the plumb bob from descending or caustic liquids that could damage the blade.

Blade refills replace worn blades on oil gauging tapes or change blades for a different material or different system of measurement. They wind onto the spindle of an oil gauging tape.