IEC TR 62471-4:2022

IEC TR 62471-4 ®
Edition 1.0 2022-09
TECHNICAL
REPORT
colour
inside
Photobiological safety of lamps and lamp systems –
Part 4: Measuring methods
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IEC TR 62471-4 ®
Edition 1.0 2022-09
TECHNICAL
REPORT
colour
inside
Photobiological safety of lamps and lamp systems –

Part 4: Measuring methods
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.140.01, 31.260 ISBN 978-2-8322-5734-0

– 2 – IEC TR 62471-4:2022 © IEC 2022
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms, definitions and abbreviated terms . 8
3.1 Terms and definitions . 8
3.2 Abbreviated terms . 10
4 Application . 10
4.1 General . 10
4.2 Safety precautions . 10
4.3 Hazard assessment overview . 10
4.4 Selection of hazards . 11
4.5 Assessment levels . 11
4.6 Initial filtering . 12
4.7 Measurement quantities . 12
4.7.1 Emission wavelengths . 12
4.7.2 Irradiance . 13
4.7.3 Radiance . 14
4.7.4 Source size and location . 16
4.7.5 Temporal emission . 18
4.8 Measurement uncertainty . 18
5 Test conditions . 19
5.1 General . 19
5.2 Dark room (level A) . 19
5.3 Environmental conditions (level A) . 19
5.4 Power supply . 19
5.5 Product configuration . 19
5.5.1 General . 19
5.5.2 Warm up . 20
5.5.3 Measurement distance . 20
5.6 Optical alignment . 22
6 Performance characteristics: level A instruments . 22
6.1 General . 22
6.2 Spectral irradiance and radiance . 23
6.2.1 Spectral analysis . 23
6.2.2 Entrance optics . 25
6.2.3 Calibration standards . 26
6.3 Imaging devices . 27
6.4 Temporal emission . 27
6.5 Source size and location . 28
7 Performance characteristics: level B instruments . 28
7.1 General . 28
7.2 Irradiance or radiance . 28
7.2.1 General . 28
7.2.2 UV lines . 29

7.2.3 Narrow band sources . 29
7.2.4 Known spectral distribution . 29
7.2.5 Luminance-based . 30
7.3 Apparent source location and subtense . 31
7.4 Temporal emission . 31
Annex A (informative) Hazard selection . 32
Annex B (informative) Instrumentation description . 33
B.1 Double monochromators . 33
B.2 Single monochromators . 33
B.3 Array spectrometers . 33
B.4 Detectors . 33
B.5 Entrance optics . 34
B.6 Measurement geometries . 36
B.6.1 Irradiance . 36
B.6.2 Radiance . 36
B.7 2D imaging detector . 39
Annex C (informative) Extrapolation of spectral irradiance for thermal radiators . 41
Annex D (informative) Temporal emission measurement . 43
D.1 General . 43
D.2 Pulse duration . 43
D.3 Averaged irradiance and averaged radiance . 44
Annex E (informative) Uncertainty analysis . 47
Annex F (informative) Application examples . 48
F.1 General . 48
F.2 Example 1 – LED flashlight . 48
F.3 Example 2 – Infrared tungsten filament lamp . 49
F.4 Example 3 – Compact fluorescent lamp (CFL) . 51
F.5 Example 4 – LED bulb . 53
Annex G (informative) Stray radiation . 54
Annex H (informative) Report . 56
H.1 General . 56
H.2 Report. 56
Annex I (informative) Relationship between "true" source radiance and spatially
averaged radiance . 58
Bibliography . 62

Figure 1 – Schematic representation of irradiance measurement . 14
Figure 2 – Consideration of filling of FOV . 15
Figure 3 – Example of a direct measurement of radiance using a lens and aperture. 15
Figure 4 – Indirect measurement of radiance . 16
Figure 5 – Example of a rectangular source . 18
Figure 6 – Example of the non-uniform radiance distribution . 18
Figure 7 – Example of the emission profiles . 22
Figure B.1 – Examples of the diffuser optics . 35
Figure B.2 – Schematic representation of irradiance measurement . 36
Figure B.3 – Geometry of radiance measurement with a single thin lens . 37

– 4 – IEC TR 62471-4:2022 © IEC 2022
Figure B.4 – Geometry of a general radiance measurement . 38
Figure B.5 – Setup of the aperture stop behind the lens . 38
Figure B.6 – Setup of the aperture stop in front of the lens . 39
Figure B.7 – Example of a 2D imaging detector . 40
Figure D.1 – Example of temporal pulse wave .
...