《BS-7691-1994.pdf》由会员分享,可在线阅读,更多相关《BS-7691-1994.pdf(18页珍藏版)》请在三一文库上搜索。
1、BRITISH STANDARD BS 7691:1994 Methods for Testing resistance to environmental conditions of electronic equipment used in agriculture and horticulture Licensed Copy: London South Bank University, London South Bank University, Sat Dec 30 06:28:26 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7691:1994
2、 This British Standard, having been prepared under the direction of the Agricultural Machinery and Implements Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 15 July 1994 BSI 07-1999 The following BSI references relate to the work on this
3、 standard: Committee reference AGE/31 Drafts for comment 92/86406 DC and 92/86407 DC ISBN 0 580 22668 9 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Agricultural Machinery and Implements Standards Policy Committee (AGE/-) to Technical
4、 Committee AGE/31, upon which the following bodies were represented: Agricultural Engineers Association Forestry Commission Health and Safety Executive Milk Marketing Board Ministry of Agriculture, Fisheries and Food National Farmers Union Silsoe College, Cranfield Institute of Technology Silsoe Res
5、earch Institute Amendments issued since publication Amd. No.DateComments Licensed Copy: London South Bank University, London South Bank University, Sat Dec 30 06:28:26 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7691:1994 BSI 07-1999i Contents Page Committees responsibleInside front cover Foreword
6、ii 1Scope1 2References1 3Definitions1 4General1 5Designation of environmental tests2 6Tests3 6.1General3 6.2Cold and dry heat (tests A, B and N)3 6.3Damp heat, steady state (test C)3 6.4Damp heat, cyclic (test D)3 6.5Impact (tests E and G)4 6.6Vibration (test F)5 6.7Corrosive atmosphere (test K)6 6.
7、8Dust (test L)7 6.9Air pressure (test M)7 6.10 Explosive atmospheres (test P)7 6.11 Liquids (test R)7 6.12 Solar radiation (test S)9 6.13 Readability of displays9 6.14 Electromagnetic compatibility (test V)10 6.15 Electrical environment (test W)10 Annex A (informative) Example of a test report12 Fig
8、ure 1 Temperature cycle for cold and dry heat test4 Figure 2 Damp heat test cycle5 Figure 3 Schematic arrangement of apparatus for particle impact test5 Figure 4 Vibration envelopes for random vibration test, applicable to locations LE, LF and LG, respectively6 Figure 5 Air pressure cycle8 Table 1 S
9、everity levels and locations for cold and dry heat tests3 Table 2 Severity levels and locations for operational mechanical shock test5 Table 3 Defining points of vibration envelopes for random vibration test6 Table 4 Severity levels and locations for dust test7 Table 5 Severity levels and locations
10、for water spray test9 Table 6 Chemicals and locations for chemical spray tests9 Table 7 Severity levels and locations for readability test for displays9 Table 8 Severity levels for electrostatic discharge test11 List of referencesInside back cover Licensed Copy: London South Bank University, London
11、South Bank University, Sat Dec 30 06:28:26 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7691:1994 ii BSI 07-1999 Foreword This British Standard has been prepared under the direction of the Agricultural Machinery and Implements Standards Policy Committee. The use of electronic equipment to monitor a
12、nd control agricultural equipment is growing rapidly. Such equipment is essential for optimizing machine operation and minimizing use of labour time, fuel and raw materials such as chemical spray and fertilizers. Without the sophistication of electronic monitoring and control, British agricultural e
13、quipment is likely to suffer further from import penetration. With it, the export potential of British equipment is greatly enhanced. The recent establishment of a British Standard (BS 7436-1:1991) for data communication on mobile agricultural equipment will contribute significantly towards that goa
14、l. To exploit potential applications, consideration has also been given to the environment in which the electronic equipment is to perform. The agricultural environment is particularly hostile and can involve extreme climatic conditions, shock and vibration, dust, slurries and fluids, some of which
15、are highly corrosive. The electronic equipment needs to withstand these conditions and operate reliably over a predictable life. It has been stated that the environmental specification for agricultural electronics can be more demanding than for military electronics. This standard is based on a draft
16、 prepared by Silsoe Research Institute under contract for BSI. Material has been drawn from a wide range of environmental standards published, inter alia, by BSI, the International Organization for Standardization (ISO), the Deutsches Institut fr Normung e.V. (DIN), the Society of Automotive Enginee
17、rs (SAE) and the American Society of Agricultural Engineers (ASAE), together with documents from commercial companies and published papers. Attention is also drawn to tests given in BS 2011-1.1:1989, BS 5772-1:1985, BS EN 61010-1:1993 and PD 6521:1988, which may be appropriate for this type of equip
18、ment. Not all tests are applicable to given equipment in a given location. BS 2011-2.1 gives guidance on test equipment. 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 wit
19、h a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 12, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had am
20、endments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: London South Bank University, London South Bank University, Sat Dec 30 06:28:26 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7691:1994 BSI 07-19991 1 Scope This British Standard gives meth
21、ods for testing resistance of on-farm electronic equipment to environmental conditions (climatic, mechanical, dynamic and electric) to which the equipment may be subjected. It gives tests for specific environmental conditions and defines severity levels for tests which relate to the environmental ex
22、tremes that may be experienced in practical operation of the equipment. NOTEThe severity levels given are general guidelines and not guaranteed worst case exposure levels. The tests are applicable to mobile and stationary equipment in both protected and exposed on-farm locations. The standard is int
23、ended to determine the suitability of on-farm equipment for use in a specified range of environmental conditions. 2 References 2.1 Normative references This British Standard incorporates, by reference, provisions from specific editions of other publications. These normative references are cited at t
24、he appropriate points in the text and the publications are listed on the inside back cover. Subsequent amendments to, or revisions of, any of these publications apply to this British Standard only when incorporated in it by updating or revision. 2.2 Informative references This British Standard refer
25、s to other publications that provide information or guidance. Editions of these publications current at the time of issue of this standard are listed on the inside back cover, but reference should be made to the latest editions. 3 Definitions For the purposes of this British Standard the definitions
26、 given in BS 2011-1.1:1989 apply, together with the following. 3.1 display device device displaying alpha-numeric characters designed to be read by operative or service personnel 3.2 equipment self-contained electronic system containing electric, electronic and mechanical components which is electri
27、cally connected to other machinery (including power sources) by means of connectors 3.3 impaired function state in which one or more of the functions of the equipment as stated by the manufacturer is not operative or does not conform to the manufacturers specification 3.4 location position within an
28、 agricultural enterprise where the equipment will normally be operating 3.5 normal mounting configuration orientation of the equipment when in service 3.6 severity level severity of the conditions under which an environmental test is undertaken, selected according to the intended location and applic
29、ation of the equipment 3.7 livestock building building used to house large farm animals (e.g. cattle) or poultry 3.8 horticultural building building in which crops are grown NOTEThis includes greenhouses and mushroom houses. 3.9 produce store building in which agricultural or horticultural produce i
30、s stored for short or long periods NOTEThis includes grain stores, vegetable stores and fruit stores. 3.10 portable equipment equipment that can be battery operated and that a person can carry 4 General 4.1 Safety of test apparatus Electronic measuring apparatus used in carrying out tests shall conf
31、orm to BS EN 61010-1:1993. 4.2 General conditions for tests Except where otherwise specified for a particular test, testing shall be carried out under standard reference conditions as specified in section 5 of BS 2011-1.1:1989. The severity levels used shall be recorded on the test report. Tests sha
32、ll be conducted in accordance with BS 5772-1:1985. The same sample of equipment shall be used in all tests unless specified otherwise for a particular test. Licensed Copy: London South Bank University, London South Bank University, Sat Dec 30 06:28:26 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 76
33、91:1994 2 BSI 07-1999 NOTEConsideration should be given to the environment and conditions in which the equipment is expected to operate. Where appropriate, combined tests should be carried out (e.g. temperature and vibration) and recorded as such on the test report. Combined testing is advisable in
34、cases where equipment is subjected in use to extremes of two or more different environmental factors simultaneously. 4.3 Test sequence The temperature tests shall be carried out first. The electromagnetic compatibility tests shall be carried out last, since electromagnetic emissions and susceptibili
35、ty can be affected by prior exposure to other tests. NOTEThe remaining tests should be carried out in a progressively increasing order of severity. The test sequence shall be recorded on the test report. 4.4 Test report The test report shall give the following information: a) description of the equi
36、pment; b) model number or other identification; c) manufacturers name and address; d) date of submission of the equipment to the conditioning process and the conditions used (see 4.5); e) the order in which the tests were conducted (see 4.3); f) severity level used for testing; g) test results; h) a
37、ny additional details regarding the test. NOTEAn example of a test report layout is given in Annex A. 4.5 Conditioning Equipment to be subjected to testing shall first be conditioned according to a climatic sequence as described in BS 2011-1.1:1989. The sequence shall consist of the following catego
38、ries: dry heat; damp heat, cyclic (test D) (see clause 5); cold; damp heat, cyclic (test D) (see clause 5). The sequence used shall be recorded on the test report in the form of three groups of digits corresponding to the minimum cold test temperature, the maximum dry heat temperature and the number
39、 of days exposure to damp heat. Example 55/100/56 represents 55 C, 100 C and 56 days. 4.6 Location of equipment The location of the equipment within an agricultural enterprise shall be classified using a two-letter code as follows: LA: stationary, protected from weather; LB: stationary, protected fr
40、om weather, in a livestock building; LC: stationary, protected from weather, in horticultural buildings and produce stores; LD: stationary, unprotected from weather; LE: mobile, protected from weather (e.g. in a tractor cab); LF: mobile, unprotected from weather; LG: mobile, in an engine compartment
41、; LH: portable. 5 Designation of environmental tests The families of tests given in this British Standard shall be designated by the following code letters (selected from BS 2011-1.1:1989 and PD 6521:1988). Acold Bdry heat Cdamp heat (steady state) Ddamp heat (cyclic) Eimpact Fvibration Goperational
42、 mechanical shocka Kcorrosive atmosphere Ldust Mair pressure Nchange of temperature Pexplosive atmospheresb Rliquidsa Rawater spray Rburea nitrogen Rcliquid lime RdNPK fertilizer (7“ % N, 7“ % P, 7“ % K compound fertilizer) Reammonium hydroxide Rgdiesel fuel Rhpetrol fuel Rjhydraulic oil Licensed Co
43、py: London South Bank University, London South Bank University, Sat Dec 30 06:28:26 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7691:1994 BSI 07-19993 6 Tests 6.1 General 6.1.1 Monitoring for impaired function Where equipment is to be monitored for impaired function during or after a test, the equ
44、ipment shall be connected to power and signal input and output lines in accordance with the manufacturers instructions. 6.1.2 Tolerances on test parameters Tolerances on test parameters shall be as follows. 6.2 Cold and dry heat (tests A, B and N) 6.2.1 Apparatus 6.2.1.1 Test chamber, capable of mai
45、ntaining the temperatures specified for the test. 6.2.2 Procedure Subject the equipment under test to the temperature cycle shown in Figure 1 using values of Tmax. and Tmin. given in Table 1. Monitor the equipment for impaired function during and at the conclusion of the test. 6.2.3 Severity levels
46、and location applicability Carry out tests at the severity levels appropriate to the relevant locations as given in Table 1. Table 1 Severity levels and locations for cold and dry heat tests 6.3 Damp heat, steady state (test C) 6.3.1 Apparatus 6.3.1.1 Test chamber, capable of maintaining the humidit
47、y and temperatures specified for the test. 6.3.2 Procedure Expose the equipment under test to 96 % relative humidity at 38 C for 240 h. Monitor the equipment for impaired function under test conditions and at the end of the test. 6.3.3 Location applicability This test is applicable to all locations.
48、 6.4 Damp heat, cyclic (test D) 6.4.1 Apparatus 6.4.1.1 Test chamber, capable of maintaining the humidity and temperatures specified for the test. 6.4.2 Procedure Expose the equipment under test to two of the test cycles shown in Figure 2 (i.e. testing for a period of 48 h). Monitor the equipment fo
49、r impaired function during and at the end of the test. 6.4.3 Location applicability This test is applicable to locations LB, LC, LD, LF, and LG. Rkethylene glycol Rlagro-chemicalsc Rxwater immersion Ssolar radiation Velectromagnetic compatibilityb Vasusceptibility Vbemissions Welectrical environmentb Wasteady state supply Wbtransient supply Wcelectrostatic discharge Wdfluctuating supply a Differs from BS 2011-1.1:1989. b Under review in BS 2011-1.1:1989. c Agro-chemicals should be recorded as water or oil based and acid or alkali based
链接地址:https://www.31doc.com/p-3736065.html