Inventory or Custody Transfer


In reference to custody transfer, Gauging Systems manufactures the MTG “Multi-functional Tank Gauge.” Currently within the U.S., custody transfer is an agreement between the buyer and seller on the means by which certification of the volume transferred is measured.

This is sort of like when you pull into a gas station to fill up the car. You put so many gallons into the car. Both API and ISO since 2002 have recognized that custody transfer can’t be measured by level and temperature alone. Other measurement factors affect volumetric accuracy. That is why you don’t pull into the gas station and put in a number of inches of gasoline into your car.

Volumetric measurements by either Hydrostatic (Mass) or Hybrid (Level, Multi-point temperature, Density, and Water) are the only methods currently accepted for custody transfer within storage tanks by API and ISO. The MTG “Multi-functional Tank Gauge” provides Hydrostatic and Hybrid volumetric measurement to custody transfer accuracy from one single instrument.

NOTE: OIML (International Organization of Legal Metrology) and its member countries have chosen to write recommendations and certify products for the legal measurement based upon the recommendations. This is the organization that some European tank gauge manufacturers reference when stating “custody transfer accuracy” in marketing their equipment. The MTG has been certified by OIML to meet standard R-125 (1998), “Measuring systems for the mass of liquids in storage tanks.” The MTG is the only gauge to date to meet this certification. The remaining ½ dozen or so gauges approved by OIML are under R-85 (1998 E) “Automatic level gauges for measuring the level of liquid in fixed storage tanks.” NOTE: This OIML standard does not cover Hybrid measurement as recognized by current API and ISO standards. Draw your own conclusions as to which is the most accurate standard, and the most accurate gauge.

For more information on the MTG “Multi-function Tank Gauge” please fill out an additional information request form. Click Here