Teledyne operating instructions NDIR CO2 Gas Detection, 10:Model 6750 NDIR Unit

Total Organic Carbon Analyzer Theory of Operation

2.4.4 NDIR CO2 Gas Detection

The key component for reliable TOC analysis is the precise and interference-free detection of CO2. The Model 6750 NDIR unit requires very little maintenance because of its ability to handle the corrosive gases generated in TOC analysis. This is due in part to its non-reflective borosilicate sample cell. It has no moving parts which further reduces the maintenance load and it uses an internal self-calibrating technique.

The NDIR unit is shown in Figure 2-10. Some of the features of the NDIR unit are as follows:

•Specific, interference-free CO2 detection

•Dual-wavelength rationing compensates for drift

•Computer-controlled for accuracy

•Sapphire protected optics

•Non-corrosive, non-reflective sample cell (borosilicate)

•No moving parts or tools required for easy maintenance and service

•No critical realignment required

Figure 2-10: Model 6750 NDIR Unit

The NDIR CO2 detector uses a completely solid state, dual wavelength ratioing technique with a single borosilicate sample cell that

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