API MPMS 2.2D:2003 pdf download.Manual of Petroleum Measurement Standards Chapter 2- Tank Calibration Section 2D- -Calibration of Upright Cylindrical Tanks Using the Internal Electro-optical Distance-ranging Method.
5 Equipment
5.1 ELECTRO-OPTICAL DISTANCE-RANGING INSTRUMENT
5.1.1 Thc 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 ±
0.00 I gon.
5.1.2 The distance-measuring part of the instrument, used for direct determination of the distances, shall have a graduanon and resolution equal to or better than ± I mm. a repeatability equal to or better than ± 2 mm. and an uncertainty equal to or better than ± 2 mm.
5.2 INSTRUMENT MOUNTING consislilig of a tripod which is firm and stable. The legs of the tripod shall be held lIrm. and steadied by suitable devices such as magnetic hearers.
5.3 LASER BEAM EMITTER having a low-power laser beam complying with IEC X25. which is either an integral part of the EODR instrument cc a separate device, lithe laser beam emitter is a separate device, it may be Iittcd with a fiber optic light transmitter system and a theodolite telescope eye. piece connection, by which the laser hewn may be transmitted through a theodolite, or such that it may be litted to a thetxlolite with its axis parallel to the axis of the thcodolite. The laser beam may be coincident with the optical axis of the telescope
rore I: The laser beam emitter is used to position target point. on ihe tank shell.
5.4 STADIA a rigid bar. usually 2 m long, such that the graduated length between the two stadia marks remains constant to within ± 0.02 mm.
5.5 EQUIPMENT FOR BOTTOM CALIBRATION
5.6 AUXILIARY EQUIPMENT including:
a. heavy weights to he set around the instrument to steady the unit:
b. lighting within the tank, if required.
6 General Considerations
6.1 The EODR instrument shall be maintained so that the values of its measurement uncertainty do not exceed the values given in this part of Chapter 2.
6.2 Tanks shall only be calibrated after they have been filled at least once with a liquid of density equal to or greater than that of the liquid which they will hold when in use.
6.3 Calibration shall be carried out without interruption.
6.4 The EODR in$ruincnt shall be wrilied prior to calibration.
The accuracy of the distance-measuring unit as well as the angular mca.suring unit shall be verified using the procedures recommended by the manufacturer.
The appropnatc proccdures given in Appendix A shall be used for thc verification of cquipmcnt in thc field.
6.5 The tank shall be free from vibration and airborne dust particles.
Noie 3: The floor of the tanks should be as free as possible from debris, dust and loose scale.
6.6 Lighting. when required. shall be placed within the tank so as not to interfere with the operation of the EODR instrument.
7 EODR Instrument Setup Within theTank
7.1 INSTRUMENT SETUP
7.1.1 The instrument shall be set up with care, according to the procedure and instructions given by the manufacturers.
7.1.2 The instrument shall be set tip so as to be stable.
If necessary, the tank bottom in the vicinity of the instrument shall be made finn and steady by placing heavy weights in the area.
API MPMS 2.2D:2003 pdf download
