In order to determine net standard volume in the oil and gas industry, it is necessary to measure the temperature of the product. Once the product temperature is known, it is possible to calculate the volume at an internationally agreed upon 'standard' temperature - typically 15°C or 60°F.

A temperature change of 1°C causes a change in volume of about 0.1%. The American Petroleum Institute (API) and American Society for Testing and Materials (ASTM) recommend a minimum of three temperature measurement devices for inventory control applications and a minimum of six points for custody transfer applications.

However, the more elements used, the more accurate the measurement. In practice, between one and sixteen temperature elements are used in a tank.