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1、BRITISH STANDARD AEROSPACE SERIES BS 2G 191: 1988 Specification for Lighting for aircraft indicators using integral filament lamps UDC 629.7.048.8:681.2.085:621.326 Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:15:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2G 191:1988 This British
2、Standard, having been prepared under the direction of the Aerospace Standards Committee, was published under the authority of the Executive Board and comes into effect on 29 February 1988 BSI 04-2000 The following BSI references relate to the work on this standard: Committee reference ACE/30 Draft f
3、or comment 86/78583 DC ISBN 0 580 16301 6 Committees responsible The preparation of this British Standard was entrusted by the Aerospace Standards Committee (ACE/-) to Technical Committee ACE/30, upon which the following bodies were represented: Civil Aviation Authority (Airworthiness Division) Mini
4、stry of Defence Society of British Aerospace Companies Limited Amendments issued since publication Amd. No.Date of issueComments Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:15:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2G 191:1988 BSI 04-2000i Contents Page Committees responsible
5、Inside front cover Forewordii 1Scope1 2Definition1 3Supply voltage1 4Colour of light source1 5Measurements1 6Luminance1 7Warning flags1 8Stray light1 9Markings to background contrast ratio by daylight2 10Reliability2 11Safety electrical connections2 Figure 1 Positioning of indicator for stray light
6、tests3 Publications referred toInside back cover Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:15:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2G 191:1988 ii BSI 04-2000 Foreword This British Standard has been prepared under the direction of the Aerospace Standards Committee and is a
7、 revision of BS G 191:1965 which is withdrawn. This revision brings the standard into line with modern instrument lighting practice, and updates the references. Aircraft indicators produced in accordance with this standard have to meet the requirements of individual aircraft applications specified b
8、y the aircraft manufacturer or the aircraft operator. For each application, the indicator manufacturer produces an individual indicator specification which will specify the lighting requirement and which is called up in the appropriate clauses of this standard. The standard has been based on the lat
9、est knowledge and experience of manufacturers of instrument integral lighting systems. 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 i
10、tself 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 4, 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
11、 indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:15:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2G 191:1988 BSI 04-20001 1 Scope This British Standard specifies requirements for the integral lighting of aircraft panel indicat
12、ors. It sets out limits of luminance which should be met so that instruments grouped on an aircraft instrument panel may have an acceptable uniformity of luminance. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Definition For the purposes of t
13、his British Standard the following definition applies. integral lighting a system of lighting wholly contained within the case of an aircraft indicator. It does not include warning lights or lighting systems consisting wholly or partly of lamps projecting from the front of the indicator in such a wa
14、y as to provide local floodlighting from outside the indicator 3 Supply voltage The lighting system shall be designed to operate with a maximum supply voltage of 5.0 V r.m.s., or 5.0 V d.c. 4 Colour of light source The colour of the light shall be either red or white. NOTEIt is preferred that only o
15、ne of these colours should be used in any one instrument. The colour of the light, with a supply of 5.0V, shall be as specified in BS 1376, class A colours. 5 Measurements 5.1 A spot photometer or a comparable alternative, colour matched to the lighting colour specified and calibrated in candelas pe
16、r square metre or foot-lamberts, shall be used to measure the brightness of the individual scale markings, pointers and characters. The same photometer may be used to check the brightness of the background. 5.2 When the final instrument is to be fitted with a cover glass reflection-reducing coating
17、to comply with BS G 211, this type of glass shall be fitted for all brightness tests. 6 Luminance NOTE 1The requirements of this clause apply to all black and white areas of the indicator, including any essential lettering. NOTE 2Any special luminance requirements for coloured areas of the display s
18、hould be stated in the individual indicator specification. In the absence of all external sources of illumination, the luminance of the indicator, measured in a direction within 10 to the normal of the part of the dial being measured, shall comply with the following. a) For indicators with white lig
19、hting, at a supply voltage of 2.7 0.05 V: b) For indicators with red lighting, at a supply voltage of 5.0V. 7 Warning flags Warning flags shall be visible when viewed under all lighting levels at which the indicator may be used. 8 Stray light NOTEThe requirements of this clause relate to instruments
20、 designed for mounting in panels within 25 of the vertical position: the requirements for instruments for use in other positions shall be agreed with the manufacturer. The lighting system shall be designed to shield all lamps from direct view when the indicator is viewed from angles of up to 60 eith
21、er side of and above its centreline and up to 30 below its centreline. The following tests shall be carried out with a supply voltage of 5.0V, and with the indicator situated on a neutral 85 % reflective surface. a) With the indicator dial in its normal orientation and with the mounting plane of the
22、 indicator case perpendicular to the surface see Figure 1(a), the maximum luminance measured on the surface shall not exceed 23.98 Cdm2(7.0 ft-L) for white lighting and 5.139 Cdm2(1.5 ft-L) for red lighting. +0 0.1 Part of indicatorLuminance Cdm2(ft-La) Pointers, flags, counters, indices (in all pos
23、itions)0.856 to 3.426 (0.25 to 1.0) Dial markings0.856 to 2.570 (0.25 to 0.75) Black areasNot more than 0.171 (Not more than 0.05) a 1 ft-L = 3.426 Cdm2 Part of indicatorLuminance Cdm2(ft-L) Pointers, flags, counters, indices (in all positions)1.713 to 6.852 (0.5 to 2.0) Dial markings1.713 to 5.139
24、(0.5 to 1.5) Black areasNot more than 0.343 (Not more than 0.1) +0 0.1 +0 0.1 Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:15:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2G 191:1988 2 BSI 04-2000 b) With the indicator dial rotated through 90 in either direction from its normal orie
25、ntation and perpendicular to the surface see Figure 1(b) and Figure 1(c), the maximum luminance measured on the surface above the centreline of the dial shall not exceed 3.426 Cdm2(1.0 ft-L) for white lighting and 0.685 Cdm2(0.2 ft-L) for red lighting. c) With the indicator dial rotated through 180
26、from its normal orientation and perpendicular to the surface see Figure 1(d), the maximum luminance measured on the surface shall not exceed 3.426 Cdm2(1.0 ft-L) for white lighting and 0.685 Cdm2(0.2 ft-L) for red lighting. 9 Markings to background contrast ratio by daylight The luminance contrast r
27、atio between white areas and background areas of the instrument dial, viewed by day-light in the range of 200 to 90 000 lux1) from any direction within 10 normal to the instrument glass, shall be not less than 13 : 1, where contrast ratio is defined as 10 Reliability 10.1 Life The design of, and the
28、 components used in, integral lighting systems shall be of such a standard and quality that they do not impose a limit on the useful life of the indicator as specified in the individual specification for the indicator. Provision may be made for lamps to be changed with the indicator mounted in the o
29、perating position. Such provision shall not affect the reliability of the indicator. 10.2 Environmental conditions The integral lighting system shall be capable of functioning correctly under the full range of environmental conditions specified in the individual specification for the indicator. 10.3
30、 Lamp failure The design of the lighting system shall be such that in the event of failure of a single lamp the indicator shall be capable of being read accurately. 11 Safety electrical connections 11.1 The lighting connections shall be either brought out on separate supply pins or as stated in the
31、individual specification for the indicator. The lamps shall be directly connected in parallel to the supply pins without series resistors. No part of the lighting circuit within the instrument shall be connected to ground. 11.2 The insulation resistance between the lighting circuit and the indicator
32、 case shall comply with BS 3G 100-4.1.1. 1) 1 foot candle (obsolete) = 10.764 lux. Luminance of white areas Luminance of background areas - Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:15:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2G 191:1988 BSI 04-20003 Figure 1 Positioning of i
33、ndicator for stray light tests (see clause 7) Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:15:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 4 blank Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:15:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2G 191:1988 BSI 04-2000 Publi
34、cations referred to BS 1376, Specification for colours of light signals. BS 3G 100, Specification for general requirements for equipment for use in aircraft. BS 3G 100-4.1.1, Electrical insulation tests. BS G 211, Specification for reflection-reducing coating of instrument windows and lighting wedge
35、s. Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:15:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2G 191: 1988 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the U
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