API MPMS 2.2D:2003 pdf download.Manual of Petroleum Measurement Standards Chapter 2—Tank Calibration
The method described in this part of API MPMS Chapter 2 is an alternative to other tank calibration methods such as the strapping method (API MPMS Chapter 2, Section 2A), the optical-reference-line method (API MPMS Chapter 2, Sec- tion 2B) and the optical-triangulation method (API MPMS Chapter 2.2C). The parts of Chapter 2 form part of a series on tank calibra- tion which also includes: Standard 2551, Measurement and Calibration of Horizontal Tanks; Standard 2552, Measure- ment and Calibration of Spheres and Spheroids; Standard 2554, Measurement and Calibration of Tank Cars ; Standard 2555, Liquid Calibration of Tanks; Recommended Practice 2556, Correcting Gauge Tables for Incrustation; MPMS Chapter 7, Calibration of Barge Tanks; MPMS Chapter 2.8A, Calibration of Tanks on Ships and Oceangoing Barges; MPMS Chapter 2.8B, Establishment of the Location of the Reference Gauge Point and the Gauge Height of Tanks on Marine Tank Vessels.
5 Equipment
5.1 ELECTRO-OPTICAL DISTANCE-RANGING INSTRUMENT
5.1.1 The angular measuring part of the instrument shall have an angular graduation and resolution equal to or better than ± 0.0002 gon*, a repeatability equal to or better than ± 0.0005 gon, and an uncertainty equal to or better than ± 0.001 gon. 2 . 5.1.2 The distance-measuring part of the instrument, used for direct determination of the distances, shall have a gradua- tion and resolution equal to or better than ± 1 mm, a repeat- ability equal to or better than ± 2 mm, and an uncertainty equal to or better than ± 2 mm. 5.2 INSTRUMENT MOUNTING consisting of a tripod which is Þrm and stable. The legs of the tripod shall be held Þrm, and steadied by suitable devices such as magnetic bearers. 5.3 LASER BEAM EMITTER having a low-power laser beam complying with IEC 825, which is either an integral part of the EODR instrument or a separate device. If the laser beam emitter is a separate device, it may be Þtted with a Þber optic light transmitter system and a theodolite telescope eye- piece connection, by which the laser beam may be transmit- ted through a theodolite, or such that it may be Þtted to a theodolite with its axis parallel to the axis of the theodolite. The laser beam may be coincident with the optical axis of the telescope Note 1: The laser beam emitter is used to position target points on the tank shell. 5.4 STADIA a rigid bar, usually 2 m long, such that the graduated length between the two stadia marks remains con- stant to within ± 0.02 mm.