Metrohm NIRS Analyzer PRO - Manual (Page 10)

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2
Hardware Familiarization
Analyzer PRO is built into a rugged, sealed stainless steel housing which is designed to withstand the
harsh production environment, including washdown.
Fiber optics are used with the Reflectance Probe design, and should always be protected from
damage and abuse. In particular, fiber bend radius should never be less than 6” (150mm). It is
strongly recommended that fibers be mounted in enclosed cable trays to minimize handling,
movement, and possible accidents.
The inside view of the instrument is as shown.
Primary components are as follows:
2.1 Lamp Housing
This contains two halogen lamps. Only one lamp is active at a time. If a lamp fails, the other is
automatically switched on, and a motor moves the Sample Illumination or “light-output” fiber to the
operating lamp. The Sample Illumination Fiber carries the light energy to the sampling point.
Note that the Lamp Housing also has a Reference Fiber for each lamp, which are routed to the
optical switch. These fibers are used to measure the background (reference) energy for each lamp.
The Optical Switch automatically moves to the correct position, based upon which lamp is in use.
2.2 Optical Switch
The Optical Switch receives the light reflected back from the sample, which has been modified by
interaction with the sample material. The other inputs to the Optical Switch are the two Reference
fibers from Lamps #1 and #2, along with a “Dark Signal” reference. The Optical Switch, under control
of the on-board electronics, measures the energy returning from the sample, compares this with the
energy level sent to the sample, and scales the signal to create an absorbance spectrum over the