This standard specifies the definition and determination method of the central light intensity and corresponding beam angle of reflector lamps. This standard applies to reflector lamps such as incandescent lamps, halogen tungsten lamps and branch discharge lamps for general lighting, but does not apply to lamps for special purposes, such as floodlights. This standard only involves the design test of lamps. GB/T 19658-2005 Measurement method of central light intensity and beam angle of reflector lamps GB/T19658-2005 Standard download decompression password: www.bzxz.net

JCS 29. 140.20
National Standard of the People's Republic of China
GB/T 19658--2005/1EC 61341:1994 Methed of measurement of center beam intensity and beam angle(s)of refleclor lamps
E(: 61311:1994.IDT)
Promulgated on 18 January 2005
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China Administration of Standardization of the People's Republic of China
Implementation on 1 August 2005
GB/T19658--2005/1EC61341;1994 This standard is equivalent to IEC61341:1994 (English version) For ease of use, the following editorial changes have been made to this standard: a) "IEC 61341\ is changed to \this standard\; b) the decimal point "\" is used instead of the comma " as a decimal point; c) the prefix of IEC61341 is deleted.
This standard is proposed by China Light Industry Federation. This standard is under the jurisdiction of the National Technical Committee for Standardization of Lighting Appliances (SAC/IC224). The drafting unit of this standard is: Lanse Instrument Co., Ltd., Jianjiang University. The main drafters of this standard are Mou Tongsheng and Wang Jianping. This standard is first formulated and cited in GB/T19658-2005/1EC61341:1994. The light output characteristics of lamps are usually expressed in luminous flux. For reflector lamps, their light output characteristics are expressed in central light intensity and beam angle. This standard aims to test and interpret these two basic characteristics of reflector lamps. The method used in this standard helps to classify lamps by beam angle and cannot be used to evaluate individual lamps. For other situations, please refer to the description of the photometric characteristics of floodlights in Technical Report No. 43 of IF. 1 Scope GB/T19658--2005/1EC61341:1994 Measurement method of central light intensity and beam angle of reflector lamps This standard specifies the definition and measurement method of central light intensity and corresponding beam angle of reflector lamps. This standard applies to reflector lamps such as incandescent lamps, vomiting lamps and gas-effect electric lamps for general lighting, and is not used for lamps for special purposes, such as projection lamps. This standard only involves the design test of lamps. 2 Definitions
This standard adopts the following definitions:
Optical beam axis
refers to the axis around which the light intensity distribution is roughly symmetrical. Note 1: The light axis is not necessarily the same as the lamp axis through the lamp holder or the lamp axis of the base of the vertical reflector (such as the lip). Note 2: When the point is symmetrical, the error is very small (negligible). 2.2
Peak intensity (I,) peak tntensity The maximum value of the luminous intensity (unit: candela), which is not necessarily on the beam axis. 2.3
Center beam intensity (I,) centerbeam intensity is the luminous intensity value measured on the axis of the beam (unit: candela). 2.4
HeamanglebZxz.net
The angle between two given straight lines on the plane passing through the axis of the beam, these two straight lines pass through the center of the front of the lamp and the luminous point with the luminous intensity as the central light intensity.
3 Basic types of light beams
The beam pattern displayed on a plane perpendicular to the axis of the beam can be divided into the following types of beams: Symmetrical beam type: That is, annular beams. For such beams, the measurement can be carried out in any two mutually perpendicular planes. A symmetrical beam type: For example, an oval or shaped beam. This beam is required to be measured in two planes passing through the main axis and the main axis (perpendicular to each other) of the projected beam pattern. An irregular beam type: This type of beam has a peak light intensity point of more than 100%. It is required to be measured in two planes. 4 General test conditions For incandescent lamps and tungsten lamps, before measuring, these lamps should be aged at their rated voltage for about 100 hours. The voltage used during the test should be equal to the rated voltage of the lamp and must be kept stable, with fluctuations within 0.5%. If the voltage range is marked on the lamp, the test voltage should be the average value of the voltage range. During the test, the lamp should not be rotated around the lamp axis. For gas discharge lamps, the lamp should be aged for 100 hours under normal working conditions before measuring. During the measurement, a standard ballast with corresponding rated input voltage and frequency should be used. At the same time, the working state of the gas safety lamp should not change. GB/r19658--2005/1EC61341:19945 Test equipment
Install the lamp in the corresponding test device. For example, an optical stand or a variable angle photometer. The installation device of the lamp should maintain a certain distance from the photodetector: that is, the distance should not be less than the minimum distance that complies with the inverse square law. When the distance is further increased, the beam intensity no longer changes. The spectral characteristics of the photodetector are corrected according to the CIE photopic spectral luminous efficiency curve. The product of the illuminance value measured by the photodetector and the square of the test distance is the luminous intensity. The position of the photodetector relative to the lamp can be changed so that the measurement is within the illumination range of the lamp. During the measurement, the distance between the lamp and the photodetector should preferably remain fixed. The normal of the photodetector should pass through the center of the front of the lamp. The test should be based on the variable angle photometry method to measure the luminous intensity distribution. If the test distance cannot be kept constant, the test should be appropriately corrected. NOTE 1 It is not necessary to achieve precise alignment of the beam axis in the projector. This requirement may be achieved in some cases. NOTE 2 Although specific descriptions of the test system are given, variations due to changes in test techniques are not taken into account. If inconsistencies occur in the test results, the test method in this standard shall prevail.
Test Procedure
Project the light onto a matte screen and observe the shape of the beam to determine which beam type it is. 6.1 For lamps with symmetrical beam type or asymmetrical beam type, if there is only one peak in the beam intensity distribution, or if there are more than one peak in the beam intensity distribution but the angle between them is less than 10°: The central intensity of such lamps is equal to the peak intensity. The peak intensity is measured by looking back to determine the position of the measurement, and its value is determined by moving the position of the lamp or photodetector and observing the reading of the photodetector and recorded as the central intensity (I). The beam angle is determined in each plane by pivoting the lamp about its axis or rotating the photodetector from the point where the reading is one-half (I./2) of the central intensity to the corresponding point on the other side of the beam axis. For lamps with asymmetrical beam patterns, it is generally necessary to rotate the lamp about its axis before making measurements so that the measurement plane coincides with the primary or secondary axis of the beam pattern. 6.2 For lamps with irregular beam patterns and where the luminous intensity distribution has more than one peak, the following procedure shall be used if the angle between the two peaks is 10° or more and the peak is at least 10% higher than the lowest intensity value between them: Measure the luminous intensity distribution (see Appendix) and simultaneously a) determine the location of the peak intensity point; b) determine the location on the distribution curve where the intensity is I./2: 1) bisect the angle between the two points; determine the intensity value at the midpoint and record it as the central intensity; e) determine the location on the distribution curve where the intensity is I./2; f) determine the beam from the two locations on the curve where the intensity is I.72. Angle. The measurement should be carried out on at least six equally spaced planes (or, if an equal light intensity distribution is drawn, at least 60 points should be measured within the illumination range).
Luminous intensity
7 Technical requirements for central light intensity and light angle
Optical axis
The central light intensity value should be recorded together with its beam angle. Beam angle
GB/T19658--2005/IEC61341:1994 Angle
For symmetrical beam types, the average value of the beam angles on different planes is used; for asymmetrical beam types, the beam angles on different planes are used to express them.
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