AS 5341:2021 LED lamps一Test methods一Energy and functional performance

AS 5341:2021 LED lamps一Test methods一Energy and functional performance. Section 5 Measurement of photometric and colorimetric quantities 5.1 General The measurements of luminous flux, luminous efficacy and luminous intensity distribution of LED lamps require the use of absolute photometry methods. Alternative means of conformance to measurement of photometric and colorimetric quantities as set out in this section are provided in Table A.2. 5.2 Luminous flux 5.2.1 Total luminous flux The measurement of total luminous flux of the device under test shall be as set out in CIE S 025/E:2015 Clause 6.2. 5.2.2 Partial luminous flux The test for the measurement of partial luminous flux is conducted for the desired cone angle, a, as set out in CIE S 025/E:2015 Clause 6.3. NOTE 1 Refer to CIE TN 010 for guidance on angular intervals for luminous intensity measurements and methodology for coordinate transformation for alignment to the optical axis of the device under test. NOTE 2 Particular energy efficiency regulations and programs use the metric “useful luminous flux when stating the luminous flux which is to be measured for lighting products. An example of the use of this metric is in European Commission Regulations: for directional LED lamps with beam angle  90°, the useful luminous flux is the flux emitted in a solid angle of u sr (corresponding to a cone with angle of 120°); and for directional LED lamps with beam angle