IEC 60825-1:2007/ISH1:2009

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Publication IEC 60825-1 (Second edition – 2007) I-SH 01

SAFETY OF LASER PRODUCTS –
Part 1: Equipment classification and requirements

INTERPRETATION SHEET 1
This interpretation sheet has been prepared by committee 76: Optical radiation safety and
laser equipment.
The text of this interpretation sheet is based on the following documents:
ISH Report on voting
76/415/ISH 76/418/RVD
Full information on the voting for the approval of this interpretation sheet can be found in the
report on voting indicated in the above table.
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Subclauses 9.2 and 9.3
These subclauses are clarified by the following:
Introduction
For emissions in the wavelength range of 400 nm to 1 400 nm, the need to perform
measurements for Condition 2 (eye loupe viewing) can be greatly reduced by recognising that
Condition 3 (unaided viewing) in many cases will be the most restrictive criterion.
Interpretation
The following table outlines the process in this interpretation of IEC 60825-1, subclauses 9.2
and 9.3.
IF THEN
Angular Subtense > 1,5 mrad @ 100 mm from Condition 2 need not be considered
the reference point
Use simplified Condition 2, C = 1
Angular Subtense ≤ 1,5 mrad @ 100 mm; or
the angular subtense is not determined
Optional for intermediate sources: Angular CAN use Figure 5 (with C determined using
Figure 5) if simplified Condition 2 is too
Subtense ≤ 1,5 mrad @ 100 mm AND >
restrictive for the application
1,5 mrad using Figure 5
December 2009 ICS 13.110; 31.260

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Rationale
Based on independent studies (see for instance reference [1]), it is found that for extended
sources and for radiation in the wavelength range of 400 nm to 1 400 nm, Condition 3 will in
most cases be more restrictive than Condition 2 for extended sources (Figure 5). The main
reason for this is the magnification of the source obtained with Condition 2. Also, the aperture
stop of Condition 2 is limited to 3,5 mm since it simulates a case where there is a high level of
ambient lighting, while Condition 3 uses a 7 mm aperture stop, as it simulates a general
viewing condition including accidental exposure.
Row 1 in the table above:
If it can be shown that the apparent source
...