Table of Contents
Advertisement
Theory of Operation
requires no wall reflectivity and is completely resistant to corrosive
gases. The NDIR unit requires no optical chopper motor or mechanical
devices but utilizes a single flashing infrared source to optically "chop"
the infrared (IR) beam, which equally irradiates CO
Using a reference eliminates water vapor interference. The non-
reflective, corrosive resistant sample cell removes the requirement for
chemically removing acid gases prior to detection.
Automatic gain control (AGC) is employed during the
reference/sample cycle to compensate for such factors as IR source
deterioration, dirty optical windows, etc. When the AGC level reaches a
predetermined threshold, an optics alarm is activated. Malfunctions of
major NDIR components are detected and indicated as an alarm,
providing "fail-safe" operation. Signal detection is completely
synchronous and because of the differential ratioing technique, drift is
virtually eliminated.
All critical optics are protected by sapphire windows. The NDIR
optical bench can be easily disassembled and windows cleaned (rarely
ever required) and reassembled within fifteen (15) minutes, without
realignment or the use of any tools.
The benefit of this absolute measuring, dual line spectral
differential analytical technique, is that it provides simple, direct
measurement of all CO
a true and accurate calibration, and precisely offsets these effects for
very accurate TOC determinations.
2.4.5 Electronic Signal Processing, Display and Control
A true, industrialized Microsoft Windows™-CE Computer offers
complete automatic control of the analyzer, including the following:
• Benchmark/Auto-Validation
• Auto-Calibration
• Auto-Cleaning
• On-Board Historical Data for up to one (1) year
• Paperless Chart Recorder
• Diagnostics
• Networking (RS-232C/485)
Teledyne Analytical Instruments
contributing factors (including background) for
2
Model 6750
/reference detectors.
2
18
Advertisement
Table of Contents
