Sensor Electronics SEC 3000, Instruction And Operation Manual

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Part Number 1460005
Revision C
Installation Category: Cat. I, Pollution Degree 2
II GENERAL DESCRIPTION
The SEC 5000 IR Evolution Infrared gas detector is a rugged reliable microprocessor based intelligent gas
detector. The SEC 5000 can be used to monitor for explosive Hydrocarbons, Alcohols, PFCs, Ammonia and
many others.
The SEC 5000
IR Evolution is ideally suited for use in harsh environments and where the costs of required
maintenance for conventional catalytic or electrochemical detectors are prohibitive. The SEC 5000
IR Evolution Infrared gas detector will perform reliably in the presence of silicone and other catalytic
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 5000
IR Evolution is a stand-alone device providing a linear continuous 4 to 20 mA output
representing 0 to Full Scale.
The SEC5000 also provides a one-wire interactive digital interface and an optional HART interface.
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 reflective surfaces, such as mirrors or beam splitters.

Performs well in the presence of high concentrations or constant background levels of hydrocarbons 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 5000
IR Evolution Infrared gas detector uses infrared absorption technology for detecting
combustible hydrocarbon gases. Gases absorb infrared light only at certain wavelengths. The
concentration of a gas can be quantified by measuring and comparing intensities in light bands where there
is significant absorption by the target gas and in bands where there is little absorption by the target gas. The
SEC 5000
IR Evolution uses an infrared light source that passes collimated light through a waveguide
containing the gas sample. At the other end of the waveguide is a multiple channel receiver. The measuring
channel intensities and the reference channel intensities are then analyzed to quantify the gas
concentration. The gas concentration is then represented at the output as a gas density measurement or a
%Vol measurement/PPM measurement (selectable).
Infrared Absorption Spectrum Example
T
ra
n
s
m
it
ta
n
c
e
Wavelength
100%
0%
Absorption
Band
Reference
Band