1、BRITISH STANDARD BS 667:2005 Illuminance meters Requirements and test methods ICS 17.180.20; 29.140.40 BS 667:2005 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 January 2005 First published December 1945 Second edition February 1968 Thir
2、d edition October 1996 Fourth edition January 2005 The following BSI references relate to the work on this British Standard: Committee reference: CPL/34/5 Special announcement in Update Standards September 2004 ISBN 0 580 44391 4 Committees responsible for this British Standard The preparation of th
3、is British Standard was entrusted by Technical Committee CPL/34, Lamps and related equipment, to Subcommittee CPL/34/5, Photometry and light classifications, upon which the following bodies were represented: Chartered Institution of Building Services Engineers GAMBICA (BEAMA Ltd.) Institution of Civ
4、il Engineers Institution of Electrical Engineers (IEE) Institution of Lighting Engineers Lighting Industry Federation Ltd. National Physical Laboratory Co-opted members Amendments issued since publication Amd. No Date CommentsBS 667:2005 BSI 28 January 2005 i Contents Page Committees responsible Ins
5、ide front cover Foreword ii Introduction 1 1S c o p e 1 2 Normative references 1 3T e r m s a n d d e f i n i t i o n s 1 4 Classification 2 5 Digital ranges and readouts 3 6 Analogue scales 3 7 Calibration and testing temperature 3 8 Power supply 3 9 Performance requirements for laboratory and fiel
6、d illuminance meters 3 10 Marking 5 Annex A (informative) Guidance on choice of meter range 6 Annex B (normative) Calibration 6 Annex C (normative) Test methods 8 Bibliography 13 Table 1 Test and calibration methods 4 Table 2 Error tolerances for illuminance meters 4 Table C.1 Example of calculation
7、 of correction factor for a high pressure sodium lamp 12BS 667:2005 ii BSI 28 January 2005 Foreword This British Standard has been prepared by Subcommittee CPL/34/5. Together with BS EN 13032-1:2004, it supersedes BS 667:1996, which is withdrawn. This British Standard specifies the requirements for
8、two types of illuminance meter: Type L: laboratory instruments, and Type F: field instruments. The error tolerances have been considered in a similar manner to that used in CIE Publication 69 1, and the definitions are based on CIE Publication 17.4 2. Error tolerances for Type L meters have been ali
9、gned with those given in BS EN 13032-1:2004, Table 3. BS EN 13032-1 specifies laboratory illuminance meters for testing luminaires only. It does not cover illuminance meters for other laboratory purposes or for field use. This new edition of BS 667 incorporates changes necessitated by the publicatio
10、n of BS EN 13032-1:2004. It does not reflect a full review or revision of the standard which will be undertaken in due course. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standar
11、d does not of itself confer immunity from legal obligations. Summary of pages This document consists of a front cover, an inside front cover, pages i and ii, pages 1 to 13 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.BS 667:2004 BS
12、I 28 January 2005 1 Introduction As lighting levels reduce, the response characteristics of the human eye change from photopic during the day through an intermediate mesopic region at dusk to a scotopic response at night time. At present, eye response functions have not been defined in the mesopic r
13、egion; research work is still in progress on this subject. Although photopic measurements are generally only applicable at lighting levels above about 10 lux, in practice lighting levels for installations are specified at values significantly below this. It is therefore necessary to make illuminance
14、 measurements with known accuracy at these lower levels to check performance against such specifications, whilst accepting that these measurements do not accurately represent the visual response. Photometric measurements, even under laboratory conditions, are more difficult to determine precisely th
15、an many other kinds of physical measurement, and in the case of illuminance meters, liability to error is increased by the fact that many of the essential components of such instruments are susceptible to variation with time and use. These errors can be minimized by care in the design of the instrum
16、ent as a whole, and also by the user in not exposing it to deleterious conditions of temperature, illumination or atmosphere. It is recommended that illuminance meters should be returned to the manufacturer, or a competent photometric testing authority at intervals as recommended by the manufacturer
17、 for checking and, if necessary, recalibration. 1 Scope This British Standard specifies performance requirements for illuminance meters for the measurement of photopic illuminance for applications other than the measurement of luminaires. It specifies the performance requirements for two types of il
18、luminance meter, Type L (laboratory instruments) and Type F (field instruments). This British Standard is applicable to meters for the measurement of planar illuminance. This standard is intended for use by meter manufacturers and users. NOTE 1 The requirements specified for a Type L meter in this s
19、tandard are identical to the requirements specified for an illuminance meter in BS EN 13032-1. However, BS EN 13032-1 specifies additional requirements which are not specified in this standard. NOTE 2 If other types of illuminance e.g. semi-cylindrical, are used, reference should be made to CIE Publ
20、ication 69:1987 1. NOTE 3 Annex A gives recommendations for the choice of meter range. 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 edition of
21、 the referenced document (including any amendments) applies. BS ISO 10526:1999, CIE standard illuminants for colorimetry. CIE Publication 18.2:1983, The basis of physical photometry. Second edition. 3 Terms and definitions For the purposes of this British Standard the following terms and definitions
22、 apply. 3.1 illuminance the luminous flux per unit area falling on a surface, usually measured in lux (lumens per square metre) 3.2 illuminance meter instrument for measuring illuminance 3.3 photoelectric cell detector of optical radiation in which the absorption of photons results in the generation
23、 of an electric current or voltage, or causes a change in electrical resistance NOTE The term “photoelectric detector” is also in use.BS 667:2004 2 BSI 28 January 2005 3.4 selective or coloured filter medium which changes the spectral distribution of radiation by transmission 3.5 colour temperature
24、temperature of the full radiator which emits radiation of the same (or nearly the same) chromaticity as the radiation considered 3.6 photometer head light sensitive detector the spectral response of which is weighted (usually by means of coloured filters) to approximate the CIE spectral luminous eff
25、iciency function V( 2) of the human eye for photopic vision, as defined in CIE 18.2, together with any cosine correction required NOTE More information on the spectral response and cosine correction is given in C.2 and in C.5 respectively. 3.7 calibration plane plane normal to the axis of the photom
26、eter head to which the measured illuminance values relate NOTE This plane should be chosen so that the readings are in accordance with the inverse square law when using a point source. In the case of a photometer head without a diffuser, this plane is the plane of the limiting aperture; for a photom
27、eter head with a plane diffuser, it is the front of the diffuser. 3.8 effective range range over which the instrument conforms to the accuracy requirements of this specification 3.9 secondary standard lamp lamp, the photometric characteristics of which are accurately known and calibrated directly ag
28、ainst a national standard 3.10 working standard lamp lamp in regular use which is calibrated at regular intervals by reference to a secondary standard lamp 3.11 secondary standard illuminance meter illuminance meter, the photometric characteristics of which are accurately known and calibrated direct
29、ly against a national standard NOTE Further definitions related to photometry are given in CIE Publication 17.4 2. 4 Classification Illuminance meters shall be classified as one of the following two types: a) laboratory illuminance meters, designated Type L, which are generally retained in a laborat
30、ory or standardizing area, and against which other equipment may be calibrated and the highest precision readings obtained. Such meters may not be suitable for site or field measurements; b) field illuminance meters, designated Type F, which are for use in the field, on site and in the working envir
31、onment. Some accuracy may have to be sacrificed in the interests of the ease of use, robustness and versatility of field meters.BS 667:2004 BSI 28 January 2005 3 5 Digital ranges and readouts NOTE 1 Many illuminance meters are provided with a digital readout with the ranges either selected by the us
32、er, or the instrument automatically selecting the range (auto-ranging). The display shall read either directly in lux, or indicate a value to be multiplied or divided by 10, 100 or 1 000. The appropriate factor shall be clear from the instrument marking. The display shall show at least three digits.
33、 NOTE 2 This allows a factor of 10 between ranges, whilst still allowing the resolution to be within 1 % at the lower end of the range. Extra digits, such as a display reading up to 1999, are useful either to give an overlap between the ranges, or to give greater sensitivity; moving decimal points,
34、and fixed zeros are helpful, particularly to less experienced users, when covering a number of ranges, as they enable direct readings in lux to be made. However, final dancing digits, which vary in a random manner, should be avoided. The digits themselves shall be large and clear enough to be easily
35、 read at a convenient angle and distance without shading the sensor. NOTE 3 Liquid crystal displays (LCDs) are frequently used because of their low power consumption compared with light emitting diodes (LEDs). NOTE 4 For meters with LCDs covering low lighting levels, a built-in lamp is useful to ena
36、ble it to be read. It is essential that care is taken both with this lamp, and with an LED display, that the reading is not affected by stray light reaching the sensor. NOTE 5 A “hold” facility for the display can be useful, enabling extra light to be switched on, or the instrument to be moved, with
37、out altering the reading. NOTE 6 The meter may be self-zeroing or it may be fitted with a zero adjustment. 6 Analogue scales For multi-range analogue illuminance meters, the factor between adjacent ranges shall not exceed four. The scales of the illuminance meters shall be marked in lux or multiples
38、 of lux with bold graduations, and so figured as to minimize the chance of error in reading, even in a poor light. NOTE 1 A built-in lamp is useful for reading the scale in poor illumination, but care should be taken that this light does not affect the readings. NOTE 2 BS 3693 gives recommendations
39、for scale marking and figuring. NOTE 3 The part of the scale below the effective range of the illuminance meter may be unmarked. 7 Calibration and testing temperature The calibration and testing of illuminance meters shall be performed in an ambient temperature of 20C2C unless otherwise indicated by
40、 the manufacturer of the instrument. NOTE Care should be taken when calibrating or using the illuminance meters at high levels of illuminance, in order to minimize the effect of high temperature. 8 Power supply For battery operated instruments a battery check or other warning shall be provided to sh
41、ow when the battery should be replaced to ensure accuracy. Mains powered instruments shall conform to Clause 9 for input voltages within the range 207 V to 253 V. 9 Performance requirements for laboratory and field illuminance meters When calibrated and tested in accordance with the clauses listed i
42、n Table 1, the meter reading error due to each factor shall not be greater than the relevant value specified in Table 2.BS 667:2004 4 BSI 28 January 2005 Table 1 Test and calibration methods Table 2 Error tolerances for illuminance meters Source of error Clause Calibration uncertainty Annex B Non-li
43、nearity C.1 Spectral correction C.2 Infra-red response C.3 Ultraviolet response C.4 Cosine correction C.5 Fatigue C.6 Temperature change C.7 Range change C.8 Source of error (Terms in parentheses are corresponding terms used in BS EN 13032-1, where these differ) Maximum acceptable error over effecti
44、ve range % of reading Type L Type F Laboratory meter Field meter Calibration uncertainty ain the range: Less than 10 000 lux 1.0 2.5 10 000 lux to 100 000 lux 1.0 3.0 Non-linearity (Linearity) in the range: Less than 10 000 lux 0.2 1.0 10 000 lux to 100 000 lux 0.2 2.0 Spectral correction V( 2) matc
45、h 1.5 3.5 Infra-red response 0.2 0.2 Ultraviolet response 0.2 0.5 Cosine correction (Cosine response) (unless marked as uncorrected) 1.5 2.5 Fatigue 0.1 0.4 Temperature change (Temperature dependence) 0.2 b 0.25 b Range change 0.1 1.0 a The standard used and errors involved should be stated. b Perce
46、nt per kelvin. NOTE 1 For digital displays displaying three significant digits there is a tolerance of 1 on the least significant digit, which corresponds to 1 % for a reading of 100 and 0.2 % for a reading of 500. NOTE 2 A meter which just meets the requirements of this standard would have a best m
47、easurement capability of 4 % (Type L) or 6 % (Type F) when used on any of its calibrated ranges. For highly coloured sources, such as light emitting diodes (LEDs), larger uncertainties would apply in practice.BS 667:2004 BSI 28 January 2005 5 10 Marking The following information shall be distinctly
48、and durably marked on the illuminance meter: a) the mark of origin (this may take the form of a trade mark, the manufacturers identification mark or the name of the vendor); b) the number of this British Standard, i.e. BS 667:2005 1) ; c) type, i.e. L or F; d) instrument identification number. To en
49、sure proper use and maintenance, the following shall be marked on the illuminance meters or otherwise made available to the purchaser: 1) spectral correction error; 2) the calibration and testing temperature; 3) the date, source used and error of the last calibration and the recommended date of the next calibration; 4) where the photoelectric cell can be disconnected from the indicating instrument they shall both be marked to ensure that the correct combination of photoelectric cel
