Liquid Cargo Test Practice Exam 2026 – The Comprehensive All-In-One Guide for Success!

Ullage is the empty space between the surface of the liquid cargo and the top of the tank. In volume calculations, you measure this headspace and use the tank’s calibration data (tables or curves) to convert that ullage height into the actual volume of liquid remaining. This works because tanks are not simple shapes, so the same liquid depth can correspond to different volumes depending on the tank geometry; the calibration data accounts for that. The ullage measurement is typically obtained with a sounding tape, gauge, or level sensor, and then read against the tank’s volume table to determine how much cargo is present. It’s not the exterior height, not the total tank capacity, and not the cargo density.