Page 95 - Sensors and Control Systems in Manufacturing

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Cha p te r
T w o

FIGURE 2.22 Hypodermic needle FIGURE 2.23 Indexing mark
quality assurance. detection.

A remote photoelectric source and detector pair inspects for pas-
sage of light through a hypodermic needle (Fig. 2.22). The small,
waterproof stainless-steel housing is appropriate for crowded machin-
ery spaces and frequent wash-downs. High signal strength allows
quality inspection of hole sizes down to 0.015 mm.
Index marks on the edge of a paper are detected by a fiber-optic
photoelectric source/detector sensor to control a cutting shear down
line (Fig. 2.23).
Liquids are monitored in a clear tank through beam sensors and
an analog control. Because the control produces a voltage signal pro-
portional to the amount of detected light, liquid mixtures and densi-
ties can be controlled (Fig. 2.24).
Remote photoelectric sensors look for the presence of holes in a
metal casting (Fig. 2.25). Because each hole is inspected, accurate
information is recorded. A rugged sensor housing an extremely high
signal strength handle dirt and grease with minimum maintenance.
The modular control unit allows for dense packaging in small
enclosures.

FIGURE 2.25 Multihole casting
FIGURE 2.24 Liquid clarity control. inspection.