Omron Z4LB V2 User manual

Cat. No. SCHA-719A
Z4LB V2
INSTRUCTION MANUAL
Parallel Beam
Linear Sensor

READ AND UNDERSTAND THIS DOCUMENT
Please read and understand this document before using the
products. Please consult your OMRON representative if you
have any questions or comments.
WARRANTY
OMRON’s exclusive warranty is that the products are free
from defects in materials and workmanship for a period of
one year (or other period if specified) from date of sale by
OMRON.
OMRON MAKES NO WARRANTY OR REPRESEN-
TATION, EXPRESS OR IMPLIED, REGARDING NON–IN-
FRINGEMENT, MERCHANTABILITY, OR FITNESS FOR
PARTICULAR PURPOSE OF THE PRODUCTS. ANY BUY-
ER OR USER ACKNOWLEDGES THAT THE BUYER OR
USER ALONE HAS DETERMINED THAT THE PRODUCTS
WILL SUITABLY MEET THE REQUIREMENTS OF THEIR
INTENDED USE. OMRON DISCLAIMS ALL OTHER WAR-
RANTIES, EXPRESS OR IMPLIED.
LIMITATIONS OF LIABILITY
OMRON SHALL NOT BE RESPONSIBLE FOR SPECIAL,
INDIRECT, OR CONSEQUENTIAL DAMAGES, LOSS OF
PROFITS OR COMMERCIAL LOSS IN ANY WAY CON-
NECTED WITH THE PRODUCTS, WHETHER SUCH
CLAIM IS BASED ON CONTRACT, WARRANTY, NEG-
LIGENCE, OR STRICT LIABILITY.
In no event shall responsibility of OMRON for any act ex-
ceed the individual price of the product on which liability is
asserted.
IN NO EVENT SHALL OMRON BE RESPONSIBLE FOR
WARRANTY, REPAIR, OR OTHER CLAIMS REGARDING
THE PRODUCTS UNLESS OMRON’S ANALYSIS CON-

FIRMS THAT THE PRODUCTS WERE PROPERLY HAN-
DLED, STORED, INSTALLED, AND MAINTAINED AND
NOT SUBJECT TO CONTAMINATION, ABUSE, MISUSE,
OR INAPPROPRIATE MODIFICATION OR REPAIR.
SUITABILITY FOR USE
THE PRODUCTS CONTAINED IN THIS DOCUMENT ARE
NOT SAFETY RATED. THEY ARE NOT DESIGNED OR
RATED FOR ENSURING SAFETY OF PERSONS, AND
SHOULD NOT BE RELIED UPON AS A SAFETY COM-
PONENT OR PROTECTIVE DEVICE FOR SUCH PUR-
POSES. Please refer to separate catalogs for OMRON’s
safety rated products.
OMRON shall not be responsible for conformity with any
standards, codes, or regulations that apply to the combina-
tion of products in the customer’s application or use of the
product.
At the customer’s request, OMRON will provide applicable
third party certification documents identifying ratings and
limitations of use that apply to the products. This information
by itself is not sufficient for a complete determination of the
suitability of the products in combination with the end prod-
uct, machine, system, or other application or use.
The following are some examples of applications for which
particular attention must be given. This is not intended to be
an exhaustive list of all possible uses of the products, nor is
it intended to imply that the uses listed may be suitable for
the products:
•Outdoor use, uses involving potential chemical contamina-
tion or electrical interference, or conditions or uses not de-
scribed in this document.
•Nuclear energy control systems, combustion systems, rail-
road systems, aviation systems, medical equipment, amuse-

ment machines, vehicles, safety equipment, and installa-
tions subject to separate industry or government regulations.
•Systems, machines, and equipment that could present a risk
to life or property.
Please know and observe all prohibitions of use applicable
to the products.
NEVER USE THE PRODUCTS FOR AN APPLICATION IN-
VOLVING SERIOUS RISK TO LIFE OR PROPERTY WITH-
OUT ENSURING THAT THE SYSTEM AS A WHOLE HAS
BEEN DESIGNED TO ADDRESS THE RISKS, AND THAT
THE OMRON PRODUCT IS PROPERLY RATED AND
INSTALLED FOR THE INTENDED USE WITHIN THE
OVERALL EQUIPMENT OR SYSTEM.
PERFORMANCE DATA
Performance data given in this document is provided as a
guide for the user in determining suitability and does not
constitute a warranty. It may represent the result of OM-
RON’s test conditions, and the users must correlate it to ac-
tual application requirements. Actual performance is subject
to the OMRON Warranty and Limitations of Liability.
CHANGE IN SPECIFICATIONS
Product specifications and accessories may be changed at
any time based on improvements and other reasons.
It is our practice to change model numbers when published
ratings or features are changed, or when significant
construction changes are made. However, some specifica-
tions of the product may be changed without any notice.
When in doubt, special model numbers may be assigned to
fix or establish key specifications for your application on
your request. Please consult with your OMRON representa-
tive at any time to confirm actual specifications of pur-
chased products.

DIMENSIONS AND WEIGHTS
Dimensions and weights are nominal and are not to be used
for manufacturing purposes, even when tolerances are
shown.
ERRORS AND OMISSIONS
The information in this document has been carefully
checked and is believed to be accurate; however, no re-
sponsibility is assumed for clerical, typographical, or proof-
reading errors, or omissions.
PROGRAMMABLE PRODUCTS
OMRON shall not be responsible for the user’s program-
ming of a programmable product, or any consequence
thereof.
COPYRIGHT AND COPY PERMISSION
This document shall not be copied for sales or promotions
without permission.
This document is protected by copyright and is intended
solely for use in conjunction with the product. Please notify
us before copying or reproducing this document in any man-
ner, for any other purpose. If copying or transmitting this
document to another, please copy or transmit it in its entire-
ty.

Z4LB V2
Parallel Beam Linear Sensor
Instruction Manual

!
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iv
Notice:
OMRON products are manufactured for use according to proper procedures
by a qualified operator and only for the purposes described in this manual.
The following conventions are used to indicate and classify precautions in
this manual. Always heed the information provided with them. Failure to
heed precautions can result in injury to people or damage to property.
DANGER Indicates an imminently hazardous situation which, if not
avoided, will result in death or serious injury.
WARNING Indicates a potentially hazardous situation which, if not
avoided, could result in death or serious injury.
Caution Indicates a potentially hazardous situation which, if not
avoided, may result in minor or moderate injury, or property
damage.
Visual Aids
The following headings will help you locate different types of information.
Note Indicates information of particular interest for efficient and con-
venient operation of the product.
→Indicates pages where additional information can be found.
1Indicates a procedure. The step numbers in the procedure
correspond to the numbers in any related illustrations.
OMRON, 1999
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted,
in any form, or by any means, mechanical, electronic, photocopying, recording, or otherwise, without the prior
written permission of OMRON.
No patent liability is assumed with respect to the use of the information contained herein. Moreover, because
OMRON is constantly striving to improve its high-quality products, the information contained in this manual is
subject to change without notice. Every precaution has been taken in the preparation of this manual. Never-
theless, OMRON assumes no responsibility for errors or omissions. Neither is any liability assumed for dam-
ages resulting from the use of the information contained in this publication.

PRECAUTIONS ix. . . . . . . . . . . . . . . . . . . . .
1 Laser Safety x. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Application Precautions xxi. . . . . . . . . . . . . . . . . . . . . . . . . .
3 Environment xxii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 Maintenance xxii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 General Precautions xxii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 Checking the Package xxiii. . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 1
Application Example 1. . . . . . . . . . . . . . . . .
1-1 Inspection for Loose Bottle Caps 2. . . . . . . . . . . . . . . .
SECTION 2
Preparations 9. . . . . . . . . . . . . . . . . . . . . . . .
2-1 Nomenclature 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-2 Wiring 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-3 Connections 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-4 Axis and Gain Adjustments 18. . . . . . . . . . . . . . . . . . . .
2-5 Sensor Installation 19. . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 3
Basic Settings 23. . . . . . . . . . . . . . . . . . . . . . . .
3-1 Selecting the Measurement Unit 24. . . . . . . . . . . . . . . .
3-2 Setting Thresholds 26. . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 4
Optional Settings 35. . . . . . . . . . . . . . . . . . . . .
4-1 Optional Functions 36. . . . . . . . . . . . . . . . . . . . . . . . . . .
4-2 Key Settings 38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-3 Selector Settings 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 5
Timing Charts 49. . . . . . . . . . . . . . . . . . . . . . .
5-1 Normal 50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-2 Peak Hold 51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-3 Bottom Hold 52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-4 Sample Hold 53. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-5 Peak-to-peak Hold 54. . . . . . . . . . . . . . . . . . . . . . . . . . .
5-6 Self-peak Hold 55. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-7 Self-bottom Hold 56. . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 6
Troubleshooting 57. . . . . . . . . . . . . . . . . . . . .
SECTION 7
Specifications and Dimensions 59. . . . . . . . . .
7-1 Specifications 60. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7-2 Dimensions 64. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

vii
About this Manual:
This manual describes the installation and operation of the Z4LB V2 Parallel Beam Lin-
ear Sensor and includes the sections described below.
Please read this manual carefully and be sure you understand the information provided
before attempting to install and operate the Z4LB V2 Parallel Beam Linear Sensor.
Section 1 provides practical information on the connections, wiring, and operation of the
Z4LB V2 with a typical application example. Read this section for a quick application ref-
erence.
Section 2 provides information on preparations that must be made before turning ON the
Sensor, such as wiring, connecting, and installing Sensors and Amplifiers.
Section 3 provides information on basic settings, such as the threshold settings for good/
improper product discriminations.
Section 4 provides information on the optional functions that can be set in addition to the
basic settings.
Section 5 provides timing charts to show the operation of the hold modes.
Section 6 provides information on error messages and remedies to be taken. Refer to
this section before requesting service from your OMRON representative.
Section 7 provides the Sensor specifications and dimensions.
WARNING Failure to read and understand the information provided in this
manual may result in personal injury or death, damage to the
product, or product failure. Please read each section in its
entirety and be sure you understand the information provided
in the section and related sections before attempting any of
the procedures or operations given.
!

ix
PRECAUTIONS
This section provides general precautions for using the Z4LB V2 Parallel Beam Linear
Sensor.
The information contained in this section is important for the safe and reliable
application of the Z4LB V2 Parallel Beam Linear Sensor. You must read this section
and understand the information contained before attempting to set up or operate a
Z4LB V2 Parallel Beam Linear Sensor.
1 Laser Safety x. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Application Precautions xxi. . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Environment xxii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 Maintenance xxii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 General Precautions xxii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 Checking the Package xxiii. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1Laser Safety
x
1 Laser Safety
The Z4LB V2 Parallel Beam Linear Sensor, is a Class 1 Laser Product according to
EN60825-1 (IEC825-1) and a Class II Laser Product according to FDA (21 CFR1040.10) (see
note). The Z4LB V2 is meant to be built into final system equipment. Pay special attention to
the following precautions for the safe use of the product:
Note: Europe: Class 1 of EN60825-1: 1994 = IEC825-1: 1993
U.S.A.: Class II of FDA (21 CFR1040.10)
1. Use this product as specified in this instruction manual. Otherwise, you may be exposed
to hazardous laser radiation.
2. Be careful not to expose your eyes directly to the laser radiation or indirectly to laser
radiation reflected from mirror or shiny surfaces.
3. To avoid exposure to hazardous laser radiation, do not displace nor remove the
protective housing during operation, maintenance, and any other servicing.
4. The user should return the product to OMRON for all repair and servicing.
5. As for other countries, observe the regulations and standards specified by each country.
Requirements from Regulations and Standards
EN60825-1 “Safety of Laser Products, Equipment Classification, Requirements and
User’s Guide”
Summary of Manufacturer’s Requirements
Require-
ments;
Classification
ments;
Sub-clause Class 1 Class 2 Class 3A Class 3B* Class 4
Description
of hazard
class
Safe under
reasonably
foreseeable
conditions
Low power;
eye protec-
tion normal-
ly afforded
by aversion
responses
Same as
Class 2. Di-
rect intra-
beam view-
ing with opti-
cal aids may
be hazard-
ous
Direct intra-
beam view-
ing may be
hazardous
High power;
diffused re-
flection may
be hazard-
ous
Protective
housing
Required for each laser product; limits access necessary for perfor-
mance of functions of the products
Safety inter-
lock in pro-
tective hous-
ing
Designed to prevent removal of the panel until accessible emission val-
ues are below the AEL (see note 2) for the class assigned
Remote con-
trol
Not required Permits easy addition of ex-
ternal interlock in laser
installation
Key control Not required Laser inoperative when key
is removed

1Laser Safety
xi
Require-
ments;
Sub-clause
ClassificationRequire-
ments;
Sub-clause Class 4Class 3B*Class 3AClass 2Class 1
Emission
warning de-
vice
Not required Gives audible or visible
warning when laser is
switched on or if capacitor
bank of pulsed laser is be-
ing charged
Attenuator Not required Gives means beside ON/
OFF switch to temporarily
block beam
Location
controls
Not required Controls so located that there is no danger
of exposure to AEL above Classes 1 or 2
when adjustments are made.
Viewing op-
tics
Emission from all viewing systems must be below Class 1 AEL’s as appli-
cable
Scanning Scan failure shall not cause product to exceed its classification
Class label Required
wording
Figures A and B and specified wording
Aperture la-
bel
Not required Specified wording required
Service
entry label
Required as appropriate to the class of accessible radiation
Override in-
terlock label
Required under certain conditions as appropriate to the class of laser
used
User in-
formation
Operation manuals must contain instructions for safe use
Purchasing
and service
information
Promotion brochures must reproduce classification labels; service manu-
als must contain safety information
Medical
products
Special calibration instructions required Special calibration instruc-
tions, means for measure-
ment and target-indicator
required
Fibre optic Cable service connections require tool to disconnect if disconnection
breaks protective housing and permits access above Class 1
* With respect to the requirements of remote interlock connector, key control, emission warn-
ing and attenuator, Class 3B laser products not exceeding five times the AEL of Class 2 in
the wavelength range of 400 nm to 700 nm are to be treated as Class 3A laser products.
Note: 1. This table is intended to provide a convenient summary of requirements. See text
of this standard for complete requirements.
2. AEL: Accessible Emission Limit
The maximum accessible emission level permitted within a particular class.
For your reference, see ANSI Z136.1-1993, Section 2.

1Laser Safety
xii
Symbol and border: black
Background: yellow
Figure A Warning label – Hazard symbol
Legend and border: black
Background: yellow
Figure B Explanatory label

1Laser Safety
xiii
FDA (Compliance Guide for Laser Products, 1985, according to 21 CFR1040.10)
Requirements Class (see note 1)
q
I IIa II IIIa IIIb IV
Performance (all laser products)
Protective
housing
R (see
note 2)
R (see
note 2)
R (see
note 2)
R (see
note 2)
R (see
note 2)
R (see
note 2)
Safety interlock R (see
notes 3,
4)
R (see
notes 3,
4)
R (see
notes 3,
4)
R (see
notes 3,
4)
R (see
notes 3,
4)
R (see
notes 3,
4)
Location of con-
trols
N/A R R R R
Viewing optics RRRRRR
Scanning safe-
guard
RRRRRR
Performance (laser systems)
Remote control
connector
N/A N/A N/A N/A R R
Key control N/A N/A N/A N/A R R
Emission indi-
cator
N/A N/A R R R (see
note 10)
R (see
note 10)
Beam attenua-
tor
N/A N/A R R R R
Reset N/A N/A N/A N/A N/A R (see
note 13)
Performance (specific purpose products)
Medical S S S S (see
note 8)
S (see
note 8)
S (see
note 8)
Surveying, lev-
eling, alignment
S S S S NP NP
Demonstration S S S S S (see
note 11)
(see
note 11)
Labeling (all laser products)
Certification &
identification
RRRRRR
Protective
housing
D (see
note 5)
D (see
note 5)
D (see
note 5)
D (see
note 5)
D (see
note 5)
D (see
note 5)
Aperture N/A N/A R R R R
Class warning N/A R (see
note 6)
R (see
note 7)
R (see
note 9)
R (see
note 12)
R (see
note 12)
Information (all laser products)
User informa-
tion
RRRRRR
Product litera-
ture
N/A R R R R R
Service in-
formation
RRRRRR

1Laser Safety
xiv
Abbreviations:
R: Required.
N/A: Not applicable.
S: Requirements: Same as for other products of that Class.
Also see footnotes.
NP: Not permitted.
D: Depends on level of interior radiation.
Footnotes:
1. Based on highest level accessible during operation.
2. Required wherever & whenever human access to laser radiation above Class I limits is
not needed for product to perform its function.
3. Required for protective housings opened during operation or maintenance, if human
access thus gained is not always necessary when housing is open.
4. Interlock requirements vary according to Class of internal radiation.
5. Wording depends on level & wavelength of laser radiation within protective housing.
6. Warning statement label.
7. CAUTION logotype.
8. Requires means to measure level of laser radiation intended to irradiate the body.
9. CAUTION if 2.5 mW cm2or less, DANGER if greater than 2.5 mW cm–2.
10.Delay required between indication & emission.
11. Variance required for Class IIb or iV demonstration laser products and light shows.
12.DANGER logotype.
13.Required after August 20, 1986.

1Laser Safety
xv
Use Precautions
EN60825-1
Require-
ments;
Classification
ments;
Sub-clause Class 1 Class 2 Class 3A Class 3B* Class 4
Remote in-
terlock
Not required Connect to room or door
circuits
Key control Not required Remove key when not in
use
Beam atten-
uator
Not required When in use prevents inad-
vertent exposure
Emission in-
dicator de-
vice
Not required Indicates laser is energized
Warning
signs
Not required Follow precautions on
warning signs
Beam path Not required Terminate beam at end of useful length
Specular re-
flection
No requirements Prevent unintentional re-
flections
Eye protec-
tion
No requirements Required if engineering and administrative
procedures not practicable and MPE ex-
ceeded
Protective
clothing
No requirements Sometimes
required
Specific re-
quirements
Training No requirements Required for all operator and maintenance
personnel
* With respect to the requirements of remote interlock connector, key control, beam attenua-
tor, and emission indicator, Class 3B laser products not exceeding five times the AEL of
Class 2 in the wavelength range of 400 nm to 700 nm are to be treated as Class 3A laser
products.
Note: This table is intended to provide a convenient summary of requirements. See text of
this standard for complete precautions.

1Laser Safety
xvi
ANSI Z136.1:1993 “American National Standard for the Safe Use of Lasers”
Control Measures for the Four Laser Classes
Control measures Classification
Engineering Controls 1 2a 2 3a 3b 4
Protective Housing
(4.3.1)
XXXXXX
Without Protective Hous-
ing (4.3.1.1)
LSO (see note 2) shall establish Alternate Controls
Interlocks on Protective
Housing (4.3.2)
llllX X
Service Access Panel
(4.3.3)
llllX X
Key Control (4.3.4) --- --- --- --- SX
Viewing Portals (4.3.5.1) --- --- MPE MPE MPE MPE
Collecting Optics
(4.3.5.2)
MPE MPE MPE MPE MPE MPE
Totally Open Beam Path
(4.3.6.1)
--- --- --- --- X
NHZ
X
NHZ
Limited Open Beam Path
(4.3.6.2)
--- --- --- --- X
NHZ
X
NHZ
Enclosed Beam Path
(4.3.6.3)
None is required if 4.3.1 and 4.3.2 fulfilled
Remote Interlock Con-
nector (4.3.7)
--- --- --- --- SX
Beam Stop or Attenuator
(4.3.8)
--- --- --- --- SX
Activation Warning Sys-
tems (4.3.9)
--- --- --- --- SX
Emission Delay (4.3.9.1) --- --- --- --- --- X
Indoor Laser Controlled
Area (4.3.10)
--- --- --- --- X
NHZ
X
NHZ
Class 3b Laser Con-
trolled Area (4.3.10.1)
--- --- --- --- X ---
Class 4 Laser Controlled
Area (4.3.10.2)
--- --- --- --- --- X
Laser Outdoor Controls
(4.3.11)
--- --- --- --- X
NHZ
X
NHZ
Laser in Navigable Air-
space (4.3.11.2)
--- --- --- SSS
Temporary Laser Con-
trolled Area (4.3.12)
l
MPE
l
MPE
l
MPE
l
MPE
--- ---
Remote Firing & Monitor-
ing (4.3.13)
--- --- --- --- --- S
Labels (4.3.14 and 4.7) XXXXXX
Area Posting (4.3.15) --- --- --- SX
NHZ
X
NHZ

1Laser Safety
xvii
Control measures Classification
Administrative & Proce-
dural Controls
1 2a 2 3a 3b 4
Standard Operating Pro-
cedures (4.4.1)
--- --- --- --- SX
Output Emission Limita-
tions (4.4.2)
--- --- --- LSO Determination
Education and Training
(4.4.3)
--- --- SSX X
Authorized Personnel
(4.4.4)
--- --- --- --- X X
Alignment Procedures
(4.4.5)
--- --- X X X X
Protective Equipment
(4.4.6)
--- --- --- --- SX
Spectator (4.4.7) --- --- --- --- SX
Service Personnel (4.4.8) l
MPE
l
MPE
l
MPE
l
MPE
X X
Demonstration with Gen-
eral Public (4.5.1)
MPE {--- X X X X
Laser Optical Fiber Sys-
tems (4.5.2)
MPE MPE MPE MPE X X
Laser Robotic Installa-
tions (4.5.3)
--- --- --- --- X
NHZ
X
NHZ
Eye Protection (4.6.2) --- --- --- --- S
MPE
X
MPE
Protective Windows
(4.6.3)
--- --- --- --- X
NHZ
X
NHZ
Protective Barriers and
Curtains (4.6.4)
--- --- --- --- S S
Skin Protection (4.6.5) --- --- --- --- X
MPE
X
MPE
Other Protective Equip-
ment (4.6.5)
Use may be required
Warning Signs and La-
bels (4.7) (Design Re-
quirements)
--- --- SSX
NHZ
X
NHZ
Service and Repairs (4.8) LSO Determination
Modification of Laser
Systems (4.9)
LSO Determination
Note: 1. LEGEND
X: Shall
S: Should
---: No requirement
l: Shall if enclosed Class 3b or Class 4
MPE: Shall if MPE is exceeded
NHZ: Nominal Hazard Zone analysis required
{: Applicable only to UV and IR Lasers (4.5.1.2)

1Laser Safety
xviii
2. LSO: Laser Safety Officer
An individual shall be designated the Laser Safety Officer with the authority
and responsibility to monitor and enforce the control of laser hazards, and to
effect the knowledgeable evaluation and control of laser hazards.
For your reference, see ANSI Z136.1-1993, Section 1.3.
Laser Product Classifications
EN
Class Description
Class 1 Lasers which are safe under reasonably foreseeable conditions of opera-
tion.
Class 2 Lasers emitting visible radiation in the wavelength range from 400 nm to
700 nm. Eye protection is normally afforded by aversion responses in-
cluding the blink reflex.
Class 3A Lasers which are safe for viewing with the unaided eye. For laser emitting
in the wavelength range from 400 nm to 700 nm, protection is afforded by
aversion responses including the blink reflex. For other wavelengths the
hazard to the unaided eye is no greater than for Class 1. Direct intra-
beam viewing of Class 3A lasers with optical aides (e.g., binoculars, tele-
scopes, microscopes) may be hazardous.
Class 3B Direct intrabeam viewing of these lasers is always hazardous. Viewing
diffuse reflections is normally safe (see note).
Class 4 Lasers which are also capable of producing hazardous diffuse reflections.
They may cause skin injuries and could also constitute a fire hazard.
Their use requires extreme caution.
Note: Conditions for safe viewing of diffuse reflections for Class 3B visible lasers are: mini-
mum viewing distance of 13 cm between screen and cornea and a maximum viewing
time of 10 s. Other viewing conditions require a comparison of the diffuse reflection
exposure with the MPE.