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Chapter 11: E. Specialized Inspection Equipment 105
Part II.E.4
Figure 11.5 Horizontal optical comparator with a 356 mm (14 in.) viewing screen, digital
readout, and edge-sensing device.
Courtesy Deltronic Corporation.
“horizontal” means that the lens system is mounted horizontally, as illustrated in
Figure 11.4. Comparators are also commercially available with a vertical lens configuration
to facilitate the staging of thin parts.
One of the features of the comparator shown in Figure 11.5 is a computerized
digital readout (DRO) located on the top of the machine. The DRO has a twoaxis
digital display for establishing measurements in the X-Y plane. In addition, a
12-character alphanumeric readout displays help messages, setup options, and the
results of calculations. A fiber-optic edge-sensing device is also shown extending
down the upper left portion of the screen. This device permits the digital readout
to precisely indicate the edges of a part. A 16-key external keypad mounted on the
lower base provides the option of using the dedicated keys as they are identified,