Question 50

The Correct Answer is B. **Innage** is the correct term because it specifically refers to the actual depth or volume of liquid (in this case, a petroleum product) measured from the bottom interior surface of a tank up to the surface of the liquid. It represents how much product is *in* the tank. **Why the other options are incorrect:** * **A) Ullage:** Ullage (or outage) refers to the empty space in a tank, measured from the top interior surface down to the liquid level. It represents the space *not* filled by the product. * **C) Outage:** Outage is often used interchangeably with ullage, referring to the void space above the liquid. While sometimes used incorrectly in certain contexts, standard petroleum gauging defines innage, not outage, as the depth of the product. * **D) Thievage:** Thievage is the term used for measuring the amount of non-petroleum material (like water or sediment) settled at the bottom of a tank, using a special paste ("water-finding paste") on a gauging tape or rod. It does not refer to the depth of the petroleum product itself.