EN 60825-1:1994/A1:2002

EUROPEAN STANDARD EN 60825-1/A1
NORME EUROPÉENNE
EUROPÄISCHE NORM July 2002
ICS 13.110; 31.260 Supersedes EN 60825-1:1994/A11:1996
English version
Safety of laser products
Part 1: Equipment classification,
requirements
and user's guide
(IEC 60825-1:1993/A1:1997)
Sécurité des appareils à laser Sicherheit von Laser-Einrichtungen
Partie 1: Classification des matériels, Teil 1: Klassifizierung von Anlagen,
prescriptions et guide de l'utilisateur Anforderungen und Benutzer-Richtlinien
(CEI 60825-1:1993/A1:1997) (IEC 60825-1:1993/A1:1997)
This amendment A1 modifies the European Standard EN 60825-1:1994; it was approved by CENELEC
on 2002-07-02. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this amendment the status of a national standard without any
alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.
This amendment exists in three official versions (English, French, German). A version in any other language
made by translation under the responsibility of a CENELEC member into its own language and notified to the
Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,
Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta,
Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2002 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60825-1:1994/A1:2002 E

Foreword
The text of amendment 1:1997 to the International Standard IEC 60825-1:1993, prepared by
IEC TC 76, Optical radiation safety and laser equipment, was approved by CENELEC as
amendment A1 to EN 60825-1:1994 on 2002-07-02 without any modification.
This amendment A1 replaces amendment A11:1996 to EN 60825-1:1994.
The following dates were fixed:
– latest date by which the amendment has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2003-07-01
– latest date by which the national standards conflicting
with the amendment have to be withdrawn (dow) 2004-01-01
__________
Endorsement notice
The text of amendment 1:1997 to the International Standard IEC 60825-1:1993 was approved by
CENELEC as an amendment to the European Standard without any modification.
__________
NORME
CEI
INTERNATIONALE
IEC
60825-1
INTERNATIONAL
STANDARD
AMENDEMENT 1
AMENDMENT 1
1997-09
PUBLICATION GROUPÉE DE SÉCURITÉ
GROUP SAFETY PUBLICATION
Amendement 1
Sécurité des appareils à laser –
Partie 1:
Classification des matériels, prescriptions
et guide de l'utilisateur
Amendment 1
Safety of laser products –
Part 1:
Equipement classification, requirements
and user's guide
 IEC 1997 Droits de reproduction réservés  Copyright - all rights reserved
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Commission Electrotechnique Internationale
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International Electrotechnical Commission
Pour prix, voir catalogue en vigueur
For price, see current catalogue

60825-1 Amend. 1  IEC:1997 – 3 –
FOREWORD
This amendment has been prepared by IEC technical committee 76: Optical radiation safety
and laser equipment.
The text of this amendment is based on the following documents:
FDIS Report on voting
76/157/FDIS 76/165/RVD
Full information on the voting for the approval of this amendment can be found in the report on
voting indicated in the above table.
___________
Page 49
8.2 Measurement of laser radiation for determining classification
Add, at the end of the second paragraph of item c), the following text:
, with the exception of those cases covered by 8.2 f) and 8.2 h).
Replace, on page 51, the text of item f) by the following text:
f) For apparent sources subtending an angle, α (determined at a distance not less than
100 mm), of less than or equal to 1,5 mrad, and within the wavelength range from 400 nm to
1 400 nm, by measuring the radiant power (W) or radiant energy (J) detectable through a
circular measurement aperture of 50 mm diameter (to simulate the collection by an optical
instrument of a stationary laser beam).
NOTE – The angle α subtended by the apparent source is determined at the nearest point of human access, but
not less than a free air distance of 100 mm. Any angular dimension that is greater than α shall be limited to
max
α , and any angular dimension that is less than 1,5 mrad shall be limited to 1,5 mrad.
max
For other sources within the wavelength range from 302,5 nm to 4 000 nm, this aperture
diameter applies for any angular subtense of the source.
In cases where, by virtue of engineering design, the closest point of human access is greater
than a distance of 14 mm from the apparent source (e.g. recessed source), the distance of the
50 mm aperture from the apparent source shall be 7,14 times the distance from the apparent
source to the closest point of human access (to simulate a 7 mm aperture placed at the closest
point of human access). However, the distance of the 50 mm aperture from the closest point of
human access shall not be more than 2 m.
To eliminate collection of errant scattered radiation, for collimated beams having a divergence
less than 5 mrad, the 50 mm aperture shall be placed at a distance of 2 m from the beam exit
aperture.
60825-1 Amend. 1  IEC:1997 – 5 –
Replace, on page 51, the first paragraph of item h) by the following text:
h) For apparent sources subtending an angle, α (determined at a distance not less than
100 mm; (see note in f) above), greater than 1,5 mrad and within the wavelength range
from 400 nm to 1 400 nm, by measuring the radiant power (W) or radiant energy (J)
detectable through a circular measurement aperture of 7 mm diameter positioned at a
distance r from the source, depending upon the angular subtense α (between a minimum
of 1,5 mrad and a maximum of α = 100 mrad) of the source.
max
The distance r of the 7 mm measurement aperture from the apparent source is determined
by:
α + 0,46 mrad
r = 100 mm
α
max
In cases where, by virtue of engineering design, the measurement aperture cannot be
placed at a distance r (e.g., recessed source), the minimum measurement distance shall be
at the closest point of human access.
Alternatively, if a 7 mm aperture could be placed within a distance r from the apparent
source, measurements can be made with a circular aperture having a diameter d between
7 mm and 50 mm depending upon the angular subtense α (between a minimum of 1,5 mrad
and a maximum of α = 100 mrad) of the source. This aperture shall be placed at a
max
distance of 100 mm from the apparent source.
The diameter d of the measurement aperture is determined by:
α
max
d = 7 mm
α + 0,46 mrad
Replace, on page 51, the last paragraph of item h) by the following text:
For the determination of the AEL, the value of the angular subtense of a rectangular or linear
source is determined by the arithmetic mean of the two angular dimensions of the source. Any
angular dimension that is greater than α or less than 1,5 mrad should be limited to α
max max
or 1,5 mrad respectively, prior to determining the mean.
Page 53
9.3 Classification procedures
Replace, on page 55, the text of item e) by the following text:
e) Time basis
The following time bases are used in this standard:
1) 0,25 s for class 2 and class 3A laser radiation within the wavelength range from
400 nm to 700 nm as determined by tables 2 and 3, respectively;
2) 100 s for laser radiation of all wavelengths greater than 400 nm except for the cases
listed in a) and c);
3) 30 000 s for laser radiation of all wavelengths less than or equal to 400 nm, and for
laser radiation of wavelengths greater than 400 nm where intentional long-term viewing is
inherent in the design or function of the laser product.

60825-1 Amend. 1  IEC:1997 – 7 –
Page 91
Subclause 13.4.1
Insert, at the beginning of the second sentence before "In the wavelength range." the
following new text:
For ocular exposure
Page 93
Subclause 13.4.2
Replace the last paragraph by the following:
For the determination of the MPE, the value of the angular subtense of a rectangular or linear
source is determined by the arithmetic mean of the two angular dimensions of the source. Any
angular dimension that is greater than α or less than 1,5 mrad should be limited to α
max max
or 1,5 mrad respectively, prior to determining the mean.
Page 95
Table 6
Delete, in the title, the word "direct."
Page 115
Annex A – Examples of calculations
Replace, on page 125, the existing text of example A.2-4 by the following new text:
Find the MPE applicable to intrabeam viewing for a 10 s exposure at a distance of 1 m from a
complex Ga-As (905 nm) laser diode array source. The source consists of two rows of 10 diodes
each that are mounted behind collimating optics. The source has an output power of 6 W and a
pulse repetition frequency F of 12 kHz. The pulse duration is 80 ns. The exit aperture (collimating
lens) is 5 cm in diameter and the emergent beam diameter is 3,5 cm at the 1/e peak irradiance
points (i.e., a 3,5 cm circular measurement aperture would collect 63 % of the beam power). The
3 –2
axial beam irradiance (average) at a distance of 1 m is 3,6 × 10 W · m . The beam divergence
is 25 mrad horizontally by 3 mrad vertically, and at a distance of 1 m from the exit aperture, the
beam size is approximately 3,0 cm by 3,8 cm, respectively.
An intrabeam photograph (using infrared film) taken at a distance of 1 m from the exit aperture
reveals that each diode subtends a projected line image 2,2 mrad long and less than 0,5 mrad
across. Each diode is separated by an angle of 3,0 mrad centre-to-centre, and the two rows are
separated by an angle of 2,3 mrad (see figure A.1). Using an infrared image converter with
an OD 4 filter to reduce glare, it is revealed that these angular separations are constant from
all viewing distances between 10 cm and 2 m (this behaviour is explained in chapter 15 of
Sliney and Wolbarsht, Safety with Lasers and other Optical Sources, New York: Plenum
Publishing Co., 1980).
60825-1 Amend. 1  IEC:1997 – 9 –
Solution
The MPE applicable to the laser diode array is the most restrictive MPE resulting from an
evaluation of each individual source and each possible grouping of the array of diodes.
However, the evaluation can be greatly simplified by using the conservative assumption that all
the radiant power originates from a single point source. This would always overstate the
hazard, and if it did not result in overly restrictive control measures, one would not have to
perform the more complex analysis of the extended source.
The determination of the applicable (most restrictive) MPE requires a trial-and-error approach, since
the MPE for a single diode, two adjacent diodes, a group of three or four, etc., and the entire array is
to be calculated; recognizing that in each case the power or energy is averaged over the angular
subtense d applicable to that grouping. It is useful to draw a map of the source to study different
combinations of diodes (see figure A.1). In addition to grouping, the applicable angular subtense
differs depending upon whether the limiting case is the MPE of an individual pulse reduced by the
repetitive pulse correction factor, C , in which case α = 1,5 mrad, or is the MPE for the train of
5 min
pulses, in which case α = 11 mrad. The total number of pulses N in a 10 s exposure is 120 000.
min
The single pulse MPE for the multiple-pulse assessment is given by (using table 6 for an 80 ns
pulse) the following:
–3 –2
H = C × 5 × 10 C C J · m
MPE,train 5 4 6
–0,25 –3 –2
= 120 000 × 5 × 10 × 2,57 C J · m
–4 –2
=6,9 × 10 C J · m
In order to compare the single pulse MPE with the average irradiance of the beam, it is
convenient to express the above MPE (expressed in terms of radiant exposure) as an
irradiance averaged over F pulses per second as follows:
E = H × F
MPE,train,F MPE,train
–4 –2 4
=6,9 × 10 C J · m × 1,2 × 10 Hz
–2
= 8,28 C W · m
The single pulse MPE for the average power assessment is given by (using table 6 for a 10 s
exposure) the following:
0,75 –2
H = 18 × t C C J · m
MPE,avg 4 6
0,75 –2
= 18 × 10 × 2,57 C J · m
–2
= 260 × C J m
The above MPE, expressed as a radiant exposure, can also be expressed as an irradiance
averaged over the 10 s exposure as follows:
E = H /t
MPE,avg MPE,avg
–2
= 260 × C J · m /(10 s)
–2
= 26 × C W · m
60825-1 Amend. 1  IEC:1997 – 11 –
E can be compared directly with the average irradiance of the beam without any other
MPE,avg
transformation.
It is useful to make a comparison between the average irradiance values given by the two different
–2 –2
assessment, i.e. E = 8,28 C W · m and E = 26 C W · m . This comparison
MPE,train,F 6 MPE,avg 6
gives an interesting result. When the ratio between the value of C for the multiple-pulse
assessment and the value of C for the averaging power assessment is less than 26/8,28 = 3,14,
the multiple pulse assessment gives the most restrictive MPE, thus E has to be used to
MPE,train,F
calculate the hazard factor. In the case where this ratio is greater than 3,14, the value to be used
is
E .
MPE,avg
If the angular subtense α is less than or equal to 1,5 mrad, the ratio described above is 1, thus
the value to be used is E . If angular subtense α is greater than 1,5 mrad or less than
MPE,train,F
11 mrad, this ratio is α/(1,5 mrad). Hence, if the angular subtense of the grouping is less
than 3,14 × 1,5 mrad = 4,71 mrad, the MPE value to be used is E , whereas if
MPE,train,F
the angular subtense is greater than 4,71 mrad, the MPE value to be used is E . If the
MPE,avg,F
angular subtense α is greater than or equal to 11 mrad, this ratio is 11/1,5 = 7,33, thus the
value to be used is E .
MPE,avg
These results are useful to simplify the calculations of this example. Otherwise it should be
necessary to compare E and E for each group to be evaluated.
train,F
MPE, MPE,avg
Single-diode group
The individual diodes subtend angles of 0,5 mrad
...