The invention discloses an obscuration type
soot particle concentration measuring device which is used for detecting the
smoke particle concentration by a dual-channel measuring technology. Namely, two optical paths and two photoelectric detectors are adopted for carrying out a
luminous flux measuring method, so that larger errors of a single-optical-path measuring
system, which are caused by environmental factors (for example, temperature and
humidity), can be effectively avoided; meanwhile, fire security problems including a
delay alarm even a leaked alarm accident and the like of a spot type photoelectric
smoke detector can be eliminated. An
optical path system structure adopted by the obscuration type
soot particle concentration measuring device disclosed by the invention is set up based on an optical spectroscope, a total reflection
prism and a reflecting alignment
assembly so as to divide the
optical path into a reference
light source and a main detection
light source. Moreover, interference caused by unstable factors of a
laser light source, a circuit
system and the photoelectric detectors can be effectively eliminated by adopting an alternative-comparison
measuring principle, i.e., referring to the time-sharing alternative measurement of the optical paths and the measured main detecting
optical path.