What are the disadvantages of Open Path Detectors?
a. Provide an average gas concentration and do not indicate the precise concentration at a given point b. Dependence on the unobstructed line of sight between beam emitter and detector c. IR source in the environment (sunlight, fires, hot objects, lamps) affect certain types of detectors causing false alarms. Only a unique beam emitter (radiation source model) flash type is immune to these false alarms. d. Operation may be impaired due to physically obscuration and other conditions that result in more than 90% reduction in beam signal in cases such as very heavy fog. (Such failures are automatically revealed in advanced systems.
