1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58cylindrical tanks Part 3: Optical-triangulation methodICS 75.180.30Petroleum and liquid petroleum p
2、roducts Calibration of vertical BRITISH STANDARDBS ISO 7507-3:2006BS ISO 7507-3:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 January 2007 BSI 2007ISBN 978 0 580 50063 3Amendments issued since publicationAmd. No. Date Commentscontrac
3、t. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.National forewordThis British Standard was published by BSI. It is the UK implementation of ISO 7507-3:2006. It supersedes BS 7723-3:1994 which is withdrawn.The UK pa
4、rticipation in its preparation was entrusted to Technical Committee PTI/12, Petroleum measurement and sampling.A list of organizations represented on PTI/12 can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a Reference numberISO
5、7507-3:2006(E)INTERNATIONAL STANDARD ISO7507-3Second edition2006-07-15Petroleum and liquid petroleum products Calibration of vertical cylindrical tanks Part 3: Optical-triangulation method Ptrole et produits ptroliers liquides Jaugeage des rservoirs cylindriques verticaux Partie 3: Mthode par triang
6、ulation optique BS ISO 7507-3:2006ii iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Precautions . 1 5 Equipment . 2 5.1 Equipment for measurement of angles 2 5.2 Stadia . 2 6 Equipment set-up and procedure . 2 6.1 Preparation of tank .
7、 2 6.2 Establishment of calibration conditions 2 6.3 Set-up of theodolites and/or total stations. 3 7 Stadia set-up and procedure . 3 8 Measurement of horizontal distance between two theodolite stations using a stadia . 3 9 Measurement of horizontal distance between two theodolite stations using a t
8、otal station . 5 10 Procedure for internal optical tank wall measurements. 5 11 Procedures for external measurements. 8 11.1 General. 8 11.2 Reference circumference measured by strapping 8 11.3 Reference distances measured between pairs of theodolite stations 10 12 Tolerances . 11 12.1 Distances bet
9、ween theodolites . 11 12.2 Horizontal angles 11 12.3 Reference circumference. 11 13 Other measurements for tank calibrations 12 13.1 Tank-bottom calibrations. 12 13.2 Other measurements and data 12 14 Calculations and development of tank capacity tables 13 14.1 From the internal procedure 13 14.2 Fr
10、om the reference circumference procedure. 13 14.3 From the reference distances between pairs of theodolites 13 14.4 Corrections 13 14.5 Tank capacity table. 13 Annex A (normative) Computation of internal radii from internal measurements 14 Annex B (normative) Determination of the radius of the circl
11、e by the least-squares method. 15 Annex C (normative) Computation of internal radii from reference circumference and external measurements. 20 Annex D (normative) Computation of internal radii from reference distances between pairs of theodolite stations 22 Annex E (informative) Calibration uncertai
12、nties . 24 Annex F (normative) Procedure for checking the theodolite(s) 36 Bibliography . 38 BS ISO 7507-3:2006iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standard
13、s is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take
14、part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is t
15、o prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility
16、that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 7507-3 was prepared by Technical Committee ISO/TC 28, Petroleum products and lubricants, Subcommittee SC 3, Static petroleum measuremen
17、t. This second edition cancels and replaces the first edition (ISO 7507-3:1993), which has been technically revised. ISO 7507 consists of the following parts, under the general title Petroleum and liquid petroleum products Calibration of vertical cylindrical tanks: Part 1: Strapping method Part 2: O
18、ptical-reference-line method Part 3: Optical-triangulation method Part 4: Internal electro-optical distance-ranging method Part 5: External electro-optical distance-ranging method BS ISO 7507-3:2006vIntroduction This part of ISO 7507 describes the calibration of vertical cylindrical tanks by means o
19、f optical triangulation using theodolites. The circumference of the tank is determined at different levels by reference to a base line, which can be either a reference circumference measured by strapping or a base line between two stations of a theodolite measured by means of a tape or by an optical
20、 method. External circumferences are corrected to give true internal circumferences. The method is an alternative to other methods such as strapping (ISO 7507-1) and the optical-reference-line method (ISO 7507-2). BS ISO 7507-3:2006blank1Petroleum and liquid petroleum products Calibration of vertica
21、l cylindrical tanks Part 3: Optical-triangulation method 1 Scope This part of ISO 7507 specifies a calibration procedure for application to tanks above 8 m in diameter with cylindrical courses that are substantially vertical. It provides a method for determining the volumetric quantity contained wit
22、hin a tank at gauged liquid levels. The measurements required to determine the radius are made either internally (Clause 10) or externally (Clause 11). The external method is applicable only to tanks that are free of insulation. This method is suitable for tanks tilted up to a 3 % deviation from the
23、 vertical provided that a correction is applied for the measured tilt as described in ISO 7507-1. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest
24、 edition of the referenced document (including any amendments) applies. ISO 7507-1:2003, Petroleum and liquid petroleum products Calibration of vertical cylindrical tanks Part 1: Strapping method 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 7507-1
25、 and the following apply. 3.1 total station theodolite with built-in distance meter that coincides with the optical axis of the instrument 4 Precautions The general precautions and safety precautions specified in ISO 7507-1 shall apply to this part of ISO 7507. BS ISO 7507-3:20062 5 Equipment 5.1 Eq
26、uipment for measurement of angles 5.1.1 Theodolite, with angular resolution equal to or better than 0,2 mgon (1 mgon = 0,25 s). Each theodolite shall be mounted on a tripod that is firm and stable. The legs of the tripod shall be steadied by means of magnetic bearers (or any equivalent system) when
27、being used for the internal method. The theodolites shall be checked either periodically or prior to the tank measurements as described in Annex F. Alternatively, a total station can be used along with a prism mounted on the other station. The total station shall meet the same requirements for the a
28、ngular measurements as the theodolites. The distance measurement shall have a resolution equal to or better than 0,1 mm. The distance meter shall be calibrated together with the used prism with an extended calibration uncertainty on the order of 1 mm or better. It shall be possible to mount the pris
29、m on the tripod in the same position as the theodolite/total station. 5.1.2 Laser-beam emitter, low-power, equipped with a device, such as a fibre-optic light-transfer system and a theodolite-telescope eye-piece connection, by which the laser beam can be transmitted through a theodolite. The laser b
30、eam shall be coincident with the optical axis of the telescope. 5.1.3 Weights, heavy, to set round the theodolite stations to prevent movement of the tank bottom plate. 5.1.4 Lighting, for use inside the tank to allow measurements to be read accurately. 5.2 Stadia Stadia, at least 2 m long, of a mat
31、erial whose thermal expansion is known. The graduated length between two marks shall be calibrated. Extended calibration uncertainty should be on the order of 0,05 mm. It shall be possible to mount the stadia on the tripod in the same position as the theodolite. NOTE The stadia is not used when the
32、calibration is carried out using a total station. 6 Equipment set-up and procedure 6.1 Preparation of tank For new tanks or for tanks after repair, fill the tank to its normal working capacity at least once and allow it to stand for at least 24 h prior to calibration. 6.2 Establishment of calibratio
33、n conditions If the tank is calibrated with liquid in it, record the depth, temperature and density of the liquid at the time of calibration. Do not make transfers of liquid during the calibration. Measure or estimate the worst-case gradient of tank-shell temperatures at the time of calibration. NOT
34、E 1 The temperature gradient is used to estimate the uncertainties of the measured tank radii (see 13.2 and E.3.5.3). NOTE 2 The highest temperature is usually found on the sunny side at the top of the tank, the lowest temperature on the shady side at the bottom of the tank. BS ISO 7507-3:200636.3 S
35、et-up of theodolites and/or total stations 6.3.1 Set up each theodolite or total station with care, according to the procedure and instructions given by the manufacturer. In addition, follow the procedures described in 6.3.2 and 6.3.3. 6.3.2 Set up the instrument so as to be stable. For the internal
36、 method, steady the bottom of the tank near the theodolite or total station by installing weights or other heavy objects around the station if there is a risk of the station moving during the calibration. Mount the legs of the tripod on magnetic bearers (or any equivalent system) to prevent the legs
37、 from sliding on the tank bottom. For the external method, drive the legs of the tripod fully home into the ground. 6.3.3 Set the bed plate of the instrument as near as possible to the horizontal. NOTE This ensures verticality of the swivel axis of the theodolite or total station. 6.3.4 The calibrat
38、ion equipment shall be placed at the site for typically 1 h in order to reach ambient temperature before commencement of the actual calibration procedure. 7 Stadia set-up and procedure 7.1 Mount the stadia on the tripod with care according to the procedure and instructions given by the manufacturer.
39、 In addition, follow the procedures described in 7.2 and 7.3. 7.2 Mount the stadia horizontally and perpendicular to the aiming axis by adjusting the device on the stadia. 7.3 Once setting-up is complete, lock the stadia in position and verify that it is horizontal and perpendicular. 8 Measurement o
40、f horizontal distance between two theodolite stations using a stadia 8.1 This procedure for determining the distance using a stadia is not recommended if the distance between the stations is above 25 m. 8.2 Take the measurement prior to the commencement of the optical readings. Set up the stadia as
41、described in Clause 7. Measure the horizontal angle, 2, subtended at the theodolite (see Figure 1) by the two marks on the stadia, using the theodolite. BS ISO 7507-3:20064 Key 1 theodolite 1 2 theodolite 2 (laser) 3 stadia mark 4 stadia aPoints T and L are interchangeable. bB, the distance between
42、the two reference marks on the stadia, equals 2 m. Figure 1 Measurement of distance between two theodolites 8.3 Compute the horizontal distance, D, between the two theodolite stations from Equation (1): 2tanBD=(1) where B is the distance between the two reference marks on the stadia (corrected for t
43、hermal expansion, if necessary); is half the angle subtended at theodolite, T, by the two reference marks. 8.4 Carry out the measurement of the angle 2 and the computation of the distance, D, a minimum of five times while turning and re-pointing the theodolite in between, and calculate and record th
44、e average value. Two standard deviations of the mean of the distance, D, shall be less than half of the tolerance given in Table 3 or the entire procedure shall be repeated. 8.5 Re-determine the distance, D, after completion of all the optical measurements described in 10.13. The average distances c
45、omputed before and after the optical measurements shall agree within the tolerances given in Table 3. If they do not, repeat the calibration procedure until a set of measurements is obtained with the average values for D at the beginning and end within the tolerances. 8.6 The average of all measurem
46、ents of distance, D, shall be used in further calculations. BS ISO 7507-3:200659 Measurement of horizontal distance between two theodolite stations using a total station 9.1 This procedure for determining the distance between theodolite stations is not recommended if the distance between the station
47、s is less than 10 m. 9.2 Set up the prism at the second tripod. 9.3 Carry out the measurement of the distance, D, a minimum of five times while turning and re-pointing the total station in between, and calculate and record the average value. Two standard deviations of the mean of the distance, D, sh
48、all be less than half of the tolerance given in Table 3 or the entire procedure shall be repeated. 9.4 Re-determine the distance, D, after completion of all the optical measurements described in 10.13. The average distances computed before and after the optical measurements shall agree within the to
49、lerances given in Table 3. If they do not, repeat the calibration procedure until a set of measurements is obtained with the average values for D at the beginning and end within the tolerances. 9.5 The average of all measurements of distance, D, shall be used in further calculations. 10 Procedure for internal optical tank wall measurements 10.1 Set up two theodolite stations inside the tank as illustrated in Figure 2 and as described in 6.3. aT and L are interchangeable theodolite and laser theodolite stations.
