Specifications
4
II GENERAL DESCRIPTION
CONVENTIONS
The following conventions are used in this manual.
Warning Statement
VDC (DC Voltage)
SEC MILLENIUM
The SEC MILLENIUM Infrared gas detector is a microprocessor based intelligent gas detector that
continuously monitors carbon dioxide gases and vapors within the specified range.
The SEC MILLENIUM is ideally suited for use in harsh environments. The SEC MILLENIUM Infrared gas
detector will perform reliably in the presence of poisoning agents and can also operate in oxygen free
environments or where high background gas levels are present. There are no known poisons that affect this
technology.
The SEC MILLENIUM is a stand-alone device providing a continuos 4 to 20 mA output.
Features
• Requires no routine calibration to ensure proper operation.
• Continuous self-test automatically indicates a fault, with fail to safe operation.
• A multi-layered filtering system protects optics from dirt and water ingress.
• Straight optical path eliminates the need for mirrors or reflective surfaces or beam splitters.
• Performs well in the presence of high concentrations or constant background levels of carbon dioxide
and in oxygen depleted atmospheres.
• Highly resistant to poisoning and etching.
• Standard 4 to 20 mA output (current source)
• Explosion proof housing designed for harsh environments.
• Smart Calibration AutoAC circuit.
Infrared Detection Technology
The SEC MILLENIUM Infrared gas detector uses infrared absorption technology for detecting carbon
dioxide gas (CO2). CO2 absorbs infrared light only at certain wavelengths. The concentration of a gas can
be measured by the difference of two channels (wavelengths), a reference and a measurement channel.
The SEC MILLENIUM uses a collimated infrared light source that passes through a waveguide, at the end of
the waveguide is a dual channel receiver. The dual channel receiver measures the intensity of two specific
wavelengths, one at an absorption wavelength and another outside of the absorption wavelength. The gas
concentration is determined by a comparison of these two values.
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