Principle Of Operation - Thermo Scientific 410i Instruction Manual

Introduction

Principle of Operation

Principle of
Operation
1-2 Model 410i Instruction Manual
Thermo Fisher Scientific is pleased to supply this CO
committed to the manufacture of instruments exhibiting high standards of
quality, performance, and workmanship. Service personnel are available for
assistance with any questions or problems that may arise in the use of this
analyzer. For more information on servicing, see the "Servicing" chapter
starting on page 7-1.
The Model 410i operates on the principle that carbon dioxide (CO
absorbs infrared radiation at a wavelength of 4.26 microns.
The sample is drawn into the Model 410i through the sample bulkhead, as
shown in Figure 1–1. The sample flows through the optical bench.
Radiation from an infrared source is chopped and then passed through a
rotating optical wheel alternating between sample and reference filters. The
radiation then enters the optical bench where absorption by the sample gas
occurs. The infrared radiation then exits the optical bench and falls on an
infrared detector. The chopped detector signal is modulated by the
alternation between the filters with an amplitude related to the
concentration of CO in the sample cell. Because infrared absorption is a
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non-linear measurement, it is necessary to transform the basic analyzer
signal into a linear output. The Model 410i uses an internally stored
calibration curve to accurately linearize the instrument output over any
range up to a concentration of either 10000 ppm (Standard) or 25% (High
Level).
The Model 410i outputs the CO
the analog outputs, and also makes the data available over the serial or
Ethernet connection.
analyzer. We are
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concentration to the front panel display,
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)
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