Principle of Operation
TM794200
Rev Ad, March 2019
15
2.3.4
Microprocessor Based
The incoming signals are analyzed by the built-in microprocessor.
A sophisticated mathematical algorithm calculates between the various
functions of the detected signal thresholds. Statistics, ratio algorithms,
data communications, diagnostics, and other functions are performed.
2.3.5
Gas Sensitivity
The SafEye IR Model uses wavelengths around the 3.4µ spectral band to
measure air flammability potential between the source and detector. At
this wavelength, all hydrocarbon materials have a strong absorption peak.
This peak enables the detector to achieve regular sensitivity LEL*m* 2.5
LEL*m or 1 LEL*mLEL*mLEL*mLEL*mLEL* could be selected using RS485
Winhost, or HART communication
However, since the desired detection information is air flammability and
the actual measurement is radiation absorption around the 3.4µ spectral
band, the detector has a different sensitivity to different gases or gas
combinations.
This difference in sensitivity is irrelevant if in the protected area the gas
composition is known. However, if in a protected area the gas composition
can vary substantially, then the difference in sensitivity should be
considered in determining the detector calibration.
