API MPMS 2.2D:2003(2009) pdf download
API MPMS 2.2D:2003(2009) pdf download.Manual of Petroleum Measurement Standards Chapter 2—Tank Calibration Section 2D—Calibration of Upright Cylindrical Tanks Using the lnternal Electro-optical Distance-ranging Method.
7.2.3 The slope distances to each ot the iwo reference target points shall be measured. Two successive readings to cads icrerence target point shall be taken. The two readings, at each point, shall agree within ± 2 mm. The average distance to each point shall he calculated. The slope distances shall be recorded.
7.2.4 Wait 15 mm and repeat 7.2.3. The repeated slope distanccs shall agree within ± 2 mm with the slope distances originally measured. The slope distances shall be rccorded
7.2.5 If the original and repeated average slope distances do not agree within ± 2 mm. detcnninc the reason ror the difference.
a lithe reason fur differences is due to the instrument and or its stability, repeat the procedure from 7.1.
Is It the enstnimeni was switched off during the determination of the differences, repeat the procedure from 7.2.1.
c. If neither a) nor b) is apprupriite. repeat the procedure from 7.2.3
d. Repeat the appropnate procedures until two successive readings agree within ±2 mm.
8 Selection of Target Points
8.1 Select two sets of target points per course, one at to
i4 of course height above the lower horitonial seam, the other
at 1/j to I4 of course height below the upper htwianinal seam. The number of target points per set, on each course of the
tank shell wall, is dependent on tank circumference. The minimum number of target points per set, as a function of Lank circurutcrence. is given in Table I and illustrated in Figure I.
8.2 The target points shall be at least 300mm from any scrtical welded scam.
9 Calibration Procedure
9.1 Sight all of the Larger points along the honrontal plane at each course location, and measure the slope distance, hot-liontal angle and vertical angle to each, as illustrated iii Figure 2.
9.2 Measure and record the slope distance. hotirontal angle and sertical angle to each o4 the reference target points.
9.3 Complete the measurements to the target points on each course prior to moving to the next course.
Note 6: Measurements should begin at the ts’ttotn course and eslend. course by course, to bc lop.
9.4 After all measurements on a course arc completed. repeat the measurements to the reference target points.
The following procedures provide a method of on-site vai- A ficajion of the equipment pnor to. and on completion of. a In calibration procedure.
The procedures shall be followed each time the instrument is switched on and brought to operating temperature. and on completion of any set of n1easuremenls at a measurement sas•
A.1 Angular Measurement Verification
A.1 .1 The following procedure assumes that the Instrument at has bccn yen tied prior to calibration using the procedures rev- to omrncndcd by the manufacturer it relics on the angular maca- ci surcmcnt accuracy of the EODR instrument, as
Note K: The angul measurement uneeruiriay of the instrument is A normally adjusted to a mmimun, by the manuiaeiurcr,
A.1.2 Set up the instrument. 1olkwing the procedures w described in Clause 7.
A.1.3 Each particular EOI)R instrument will have nulnufacmrers instructions concerning collimation of both the vertical and horiiontal angular measurement components of the instrument. These instructions shall be followed exactly, and the uncerlaints of both the vertical and horizontal angular measurement components of the instrument calculated and recorded.
Al .4 The collimation uncertainty of both the horizontal and vertical components of the Instrument shall not exceed ±0.001 gon.
A.2 Distance Measurement Verification
A.2.l Comp1ere the procedures in A• I hefcmre venfmg the distance•measurernenr component of the instrument.
A.2.2 Set up the stadia using the procedures given in API MPMS Chapter 2.2C.
A.2.3 Place the stadia at a distance between 5 ni and IS m from the instnimen and nomsal to an imaginary line between the jnstnlrnent and the center mark of the siadia, as illustrated in Figure A-I.
A,2.4 tising the EODR instrument, measure the horizontal angle 21) subtended at the instrumdnt by the two marks on the stadia.
