Refrigerated hydrocarbon and non-petroleum based liquefied gaseous fuels. Calibration of membrane tanks and independent prismatic tanks in ships. Manual and internal electro-optical distance-ranging methods|Freight transport, Liquefied gases, Liquid-level measurement, Cargo ships, Water transport engineering, Ships, Dimensional measurement, Calibration, Mathematical calculations, Refrigeration, Membranes, Error correction, Aliphatic hydrocarbons, Ships bodies, Errors, Tankers, Tanks (containers), Safety measures, Volume measurement, Liquefied petroleum gas, Marine transport, Hull compartments, Liquefied natural gas, Test equipment, Prismatic shape, Testing conditions, Petroleum products