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1、BRITISH STANDARD BS 1610-3: 1990 Materials testing machines and force verification equipment Part 3: Specification for the grading of the forces applied by deadweight and lever creep testing machines Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 06:05:49 GMT+00:00 2006, Uncontrolled Copy, (
2、c) BSI BS 1610-3:1990 This British Standard, having been prepared under the direction of the Iron and Steel and the Non-ferrous Metals Standards Policy Committee, was published under the authority of the Board of BSI and comes into effect on 31 January 1991 BSI 02-1999 The following BSI references r
3、elate to the work on this standard: Committee reference ISM/NFM/4 Draft for comment 87/40632 DC ISBN 0 580 17546 4 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Iron and Steel Standards Policy Committee (ISM/-) and the Non-ferrous Meta
4、ls Standards Policy Committee (NFM/-) to Technical Committee ISM/NFM/4, upon which the following bodies were represented: Aluminium Federation British Gas plc British Non-ferrous Metals Federation British Railways Board British Steel Industry Copper Development Association Department of Trade and In
5、dustry (National Engineering Laboratory) Department of Trade and Industry (National Physical Laboratory) ERA Technology Ltd. GAMBICA (BEAMA Ltd.) Ministry of Defence Society of British Aerospace Companies Ltd. Welding Institute The following body was also represented in the drafting of the standard,
6、 through subcommittees and panels: Electricity Association Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 06:05:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1610-3:1990 BSI 02-1999i Contents Page Committees responsibleInside front
7、cover Forewordii Section 1. General 1.1Scope1 1.2Definitions1 Section 2. Grading of creep testing machines 2.1General2 2.2Lever creep testing machines2 2.3Deadweight creep testing machines2 2.4Certificate of grading2 2.5Frequency of reverification2 Section 3. Method of verification 3.1General4 3.2Re
8、solution4 3.3Verification4 3.4Preliminary procedure6 3.5Verification procedure7 3.6Calculation of results7 Figure 1 Tensile creep testing machine loading systems5 Table 1 Grading of deadweight and lever creep testing machines2 Publication(s) referred toInside back cover Licensed Copy: sheffieldun sh
9、effieldun, na, Fri Nov 24 06:05:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1610-3:1990 ii BSI 02-1999 Foreword This Part of BS 1610 has been prepared under the direction of the Iron and Steel Standards Policy Committee and the Non-ferrous Metals Standards Policy Committee. Part 1 of BS 1610 sp
10、ecifies requirements for the grading of the forces applied by a materials testing machine and the method of verification. Part 2 of BS 1610 specifies requirements for the grading of force verification equipment and the method of calibration of proving devices. It has been found that a new Part of BS
11、 1610 is required as Parts 1 and 2 do not adequately cover requirements for creep testing. This Part of BS 1610 specifies requirements for the grading of the forces applied by deadweight and lever creep testing machines and describes the method of verification. Cognizance has been taken of discussio
12、ns in the International Organization for Standardization (ISO) and the International Organization for Legal Metrology (OIML). A numerical system of grading is specified which relates to that being adopted internationally and is also conceptually similar to the system for testing machines specified i
13、n Parts 1 and 2 of BS 1610. For each grade of the verification equipment, the numerical value of repeatability has been defined as five times better than that required for the corresponding grade of the test machine. Some parameters adopted in this Part of BS 1610 differ slightly from international
14、views because they have been chosen as a result of national experience and to maintain conformity with a wide range of commercial interests. This Part of BS 1610 does not restrict the type of equipment used for verification but, by reference to Part 2 of BS 1610, requires that calibration forces be
15、traceable to national standards held at the National Physical Laboratory, either directly or indirectly through a hierarchical chain such as that provided by a calibration laboratory accredited by the National Measurement Accreditation Service (NAMAS). Traceability to national standards of other cou
16、ntries is acceptable, provided these standards are recognized by NPL. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immu
17、nity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 8, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the
18、 amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 06:05:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1610-3:1990 BSI 02-19991 Section 1. General 1.1 Scope This Part of BS 1610 specifies requirements for the grading of the forces applied by deadwei
19、ght and lever creep testing machines, and describes the method of verification. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 1.2 Definitions For the purposes of this Part of BS 1610 the following definitions apply. 1.2.1 creep testing machine a
20、 machine used for applying a constant or changing load to a test specimen for an extended period of time, usually at an elevated temperature for the purposes of creep, creep rupture or stress-relaxation testing NOTEDetails of creep testing procedures are given in BS 3500 1.2.2 SI unit of force the f
21、orce that, when applied to a mass of 1 kg, gives the mass an acceleration of 1 m/s2, i.e. the newton (N) 1.2.3 force-measuring system a system for measuring force by means of an analogue or digital display or a chart recorder NOTEEach form of display and each range in a multi-range machine is an ind
22、ependent force-measuring system 1.2.4 loading mode the direction of an increasing force, either tensile or compressive 1.2.5 repeatability the greatest difference between the true forces corresponding to repeated applications of the indicated force 1.2.6 error the error is the indicated force minus
23、the mean true force, corresponding to repeated applications of the indicated force 1.2.7 resolution the smallest increment of force that may be applied to a testpiece NOTEMethods for determining the resolution of the various categories of machine are given in 3.2.1 to 3.2.3 1.2.8 lower limit of veri
24、fication the lowest specified force on a given measurement range to which a creep testing machine can be verified 1.2.9 verification equipment equipment consisting of proving devices, verification masses and proving levers (see BS 1610-2) 1.2.10 proving device a device that determines force by the m
25、easurement of the elastic deflection of a loaded member 1.2.11 deflection a value obtained by subtracting the reading of the deflection-measuring indicator of the proving device at zero force from the reading with a force applied 1.2.12 lever ratio the multiplication factor, R, determined during cal
26、ibration over a range of forces, relating the magnitude of the masses applied to the scale pan to the force measured in the specimen loading train 1.2.13 verification masses a set of masses reserved for calibration purposes only 1.2.14 working masses the masses used to apply a load to a test specime
27、n during creep testing Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 06:05:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1610-3:1990 2 BSI 02-1999 Section 2. Grading of creep testing machines 2.1 General Uniaxial creep testing machines shall be graded in accordance with the maximum permi
28、ssible values given in Table 1 for the repeatability and error of the forces specified in 2.2 and 2.3, when verified in accordance with section 3. NOTEA creep machine may normally be regarded as a single range materials testing machine. Table 1 Grading of deadweight and lever creep testing machines
29、2.2 Lever creep testing machines At least five approximately equispaced consecutive forces, from the maximum to be verified downwards, shall not exceed the values given in Table 1 for a specific grade. The grading shall cease to apply below the minimum force that complies with these requirements. It
30、 is possible for a range to be given more than one grading, but for each such grading, all forces from the maximum downwards shall be considered. Thus a more exacting grade shall not be introduced to cover some intermediate part of the range. 2.3 Deadweight creep testing machines Each range shall be
31、 graded as described in 2.2. Machines with guides below the testpiece, which could introduce friction effects, shall be calibrated using a proving device. The verifier shall be satisfied that the axis of loading is through the longitudinal axis of the testpiece, see 3.4. NOTENormally the grading wil
32、l be determined by the accuracy of the masses and of the mass of the load suspension system below the testpiece. 2.4 Certificate of grading When a creep testing machine has been graded and verified in accordance with this Part of BS 1610, the verifier shall issue a certificate stating the following:
33、 a) the identity and location of the creep testing machine and the date of verification; b) the grade, mode and range of forces on each force-measuring system verified; c) where appropriate, any force-measuring systems that were not verified; d) the average lever ratio for each force measuring syste
34、m; e) the resolution of the testing machine (see 3.2); f) the method of verification used (see 3.5) and the identity, grading and date of the certificate of grading of the verification equipment used; g) the average temperature of the verification equipment at the time of verification; h) if verific
35、ation masses are employed, details of the method, the date of their reverification and identity of any equipment used together with details of its certified traceable route to the national primary standards; i) details of the certified verification route to the national primary standards used to ver
36、ify the working masses. 2.5 Frequency of reverification 2.5.1 Lever machines A creep testing machine shall be reverified annually if it is used for short term tests, the number of which exceeds 20 tests per annum. Machines used for long term tests shall be reverified after 20 tests or an interval of
37、 3 years whichever is the shorter, unless a long term test is in progress. In the case of multi-testpiece string machines of the type having more than one load train within a single furnace, the entire machine shall be reverified at an interval of not more than 3 years unless a long term test is in
38、progress. The individual load trains shall be reverified after 20 tests or after 3 years, whichever is the shorter. NOTECareful management of testing schedules will need to be applied in order to minimize the down time of some of the load trains pending the availability of the entire machine for rev
39、erification. Long term tests should not be set up on the various levers with continually overlapping fracture lifetimes thereby extending the reverification period. Machines shall also be reverified prior to carrying out a test if the estimated test life exceeds 3 years from the last verification. A
40、ny machine shall also be reverified if it has been dismantled for moving or subject to major repair or adjustment. Grade of machine Maximum permissible repeatability of forces as percentage of nominal force Maximum permissible error of forces as percentage of nominal forcea % 0.5 1.0 2.0 0.5 1.0 2.0
41、 0.5 1.0 2.0 a In the case of a reverification carried out using verification masses, the maximum permissible error of force, expressed as a percentage of the nominal force for the various grades given in Table 1, is the algebraic sum of the error plus the tolerance error of the working masses. If d
42、edicated masses are used for the machine reverification, the masses are effectively an integral part of the machine and thus no separate allowance need be made for the tolerance of the dedicated masses. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 06:05:49 GMT+00:00 2006, Uncontrolled Copy
43、, (c) BSI BS 1610-3:1990 BSI 02-19993 2.5.2 Machines with load measuring devices Machines incorporating a load measuring device as the primary means of measuring the force shall be reverified in accordance with BS 1610-1. The reverification shall be annual except where machines are used for long ter
44、m tests. These shall be reverified after 20 tests or an interval of 3 years whichever is the shortest, unless a long term test is in progress. In the case of multi-testpiece string machines of the type having more than one load train within a single furnace, the entire machine shall be reverified at
45、 an interval of not more than 3 years unless a long term test is in progress. The individual load trains shall be reverified after 20 tests or after 3 years, whichever is the shorter. Machines shall also be reverified prior to carrying out a test if the estimated test life exceeds 3 years from the l
46、ast verification. Any machine shall also be reverified if it has been dismantled for moving or subject to major repair or adjustment. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 06:05:49 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1610-3:1990 4 BSI 02-1999 Section 3. Method of verificat
47、ion 3.1 General The forces applied by creep testing machines shall be verified according to the procedure described in 3.5 so as to permit a determination of grading for repeatability and error of force. To ensure that the grading is consistent with the resolution of the force indication, a lower li
48、mit of verification shall be determined. NOTEFigure 1 illustrates tensile creep machine loading systems. 3.2 Resolution 3.2.1 Overslung lever creep testing machines The resolution shall be determined by a precalibration procedure under nominally zero force to ascertain the smallest force applied to
49、the testpiece necessary to cause a freely balanced lever to move a predetermined amount. The loading train shall either be disconnected above the specimen fixing or removed, whichever is most practical, and the lever balanced in the normal horizontal position as specified in 3.4.3. The amount the lever moves shall be determined either by monitoring the displacement of the loading train at the testpiece attachment position, ensuring that movement of at least 1 mm is attained by the addition of small masses on the scale pan; or by monitoring the angular movement of t
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