Service manual

MDS E-SCAN MPR E-SCAN INFORMATION
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4. MPR E-Scan Information
4.1 Technical Description
4.1.1 Sensing Head
The MPR E-Scan uses an LED as a light
source and utilizes state of the art CCD
(charge coupled device) technology to
accomplish scanning the reflected light
returned from the prism.
4.1.1.1 Optics
Light radiated from the LED passes through
the prism surface to be reflected off mirror 1
to the prism-to-process interface. The light
reaching this interface intersects the same
interface over a series of angles chosen to
include critical angle for the process being
measured. Light intersecting the interface
at an angle greater than critical angle is
refracted into the solution. Light
intersecting the interface at less than critical
angle is reflected up to mirror 2 and out of
the prism up to the CCD linear array to be
scanned.
Optical Path