IFM Electronic Efector 200 Installation guide

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Photoelectric sensors
Training manual
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ifm electronic
Sensors, networking
and control technology for
automation
Training manual
R
Photoelectric sensors

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Photoelectric sensors
Training manual
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Training manual photoelectric sensors (as in March 2003)
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Since it is impossible to avoid mistakes despite intensive efforts, we always appreciate indications.
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Photoelectric sensors
Training manual
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Contents
1 Introduction 6
1.1 Photoelectric sensors in industrial applications 6
1.2 Notation 8
1.3 On the contents 8
2 Light 10
2.1 Electromagnetic waves 10
2.1.1 Nature of the light 10
2.1.2 Ranges of wave length 12
2.1.3 Origin of light 15
2.1.4 Radiation spectrum 18
2.2 Radiation and temperature 21
2.2.1 Black emitters 21
2.2.2 Emission 21
2.2.3 Reflection and colour 22
2.3 Laser 24
2.3.1 Meaning 24
2.3.2 Features 25
2.3.3 Terms 27
2.3.4 Laser sensors 28
2.4 Refraction 29
3 Characteristics of photoelectric sensors 32
3.1 Comparison with other types of sensors 32
3.1.1 Definition 32
3.1.2 Immunity to interference of different sensor types 33
3.1.3 Ranges of sensor systems 33
3.2 Through-beam sensors 34
3.2.1 Operating principle 34
3.2.2 Information on the use of through-beam sensors in practice 38
3.3 The retro-reflective sensor 43
3.3.1 Operating principle 43
3.3.2 Use of retro-reflective sensors in practice 48
3.3.2.1 Sensors with polarisation filter 48
3.3.2.2 Laser units and prismatic reflectors 50

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Photoelectric sensors
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3.3.2.3 Prismatic reflector 51
3.3.2.4 Summary 53
3.4 Diffuse reflection sensors 54
3.4.1 Operating principle 54
3.4.2 Notes on the use of diffuse reflection sensors in practice 56
3.4.2.1 Range 56
3.4.2.2 Setting 58
3.4.2.3 Background suppression 60
3.4.2.4 Summary 64
3.4.3 Units with special features 65
3.5 Fibre optics 67
3.5.1 Typical applications 67
3.5.2 Operating principle 68
3.5.3 Notes on the use of fibre optics in practice 71
3.6 Light-on and dark-on mode 73
3.7 Excess gain 76
3.7.1 Meaning 76
3.7.2 Setting 78
3.8 Switching frequency 80
4 Examples of photoelectric sensors 83
4.1 Technology 83
4.1.1 Circuitry 83
4.1.2 Operational reliability and failure warning 85
4.2 Current and voltage ranges 91
4.2.1 Leakage current, minimum load current and voltage drop 92
4.2.2 Connection 92
4.3 Handling 97
4.3.1 Setting of the sensing range 97
4.3.1.1 OG as through-beam sensor 98
4.3.1.2 OG as retro-reflective sensor 98
4.3.1.3 OG as diffuse reflection sensor 100
4.3.1.4 OGH as diffuse reflection sensor with background suppression 102
4.3.1.5 Displays and other settings 102
4.3.2 Timers 106
4.4 Mechanical properties 112
4.4.1 Designs and ranges 112
4.4.2 Mounting 112
4.4.3 Lens attachment 122
4.5 Overview 122

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Photoelectric sensors
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4.6 Units with special properties 125
4.6.1 Side or front lens 125
4.6.2 Separate amplifier 125
4.6.3 Contrast sensor 127
4.6.4 Colour sensor 128
5 Infrared sensors 131
5.1 Operating principle 131
5.1.1 Radiation 131
5.1.2 Degree of emission 132
5.1.3 Technology 133
5.2 Information on practical use 135
5.2.1 Angle of aperture 135
5.2.2 Setting instructions for OWI 139
5.2.3 Operating conditions 140
6 Applications 143
6.1 Photoelectric sensors 143
6.1.1 Recommended sensor types 143
6.1.2 Application examples 144
6.2 Infrared sensors 150
Annex 159
Type keys 159
Production code 163
Table degree of emission 164
Table range on prismatic reflectors 166
Glossary of technical terms 170
Index 174