Title of Document: Analyzing Photo-electric Smoke Detector Response Based on Aspirated Smoke Detector Obscuration Analyzing Photo-electric Smoke Detector Response Based on Asprirated Smoke Detector Obscuration
Accurate obscuration levels at the response time of photo-electric smoke detectors are needed for proper detection modeling and analysis. In recent works, obscuration meters were used to measure the obscuration level at photo-electric detector response. In this study, aspirated smoke detectors (VESDA) were used to measure this same obscuration level. These detailed measurements were used to reduce the ambient light and the technology difference error associated with the obscuration meters. The use of aspirated smoke detection (VESDA) instead of light obscuration meters displayed increased accuracy for a majority of the experiments conducted in the 2008 report titled " Validation of a Smoke Detection Performance Prediction Methodology " involving flaming and non-flaming incipient fire sources at 3 different ventilation conditions.
Design of Detection Systems
Fire detection and alarm systems are recognized as key features of a building’s fire prevention and protection strategy. This chapter presents a systematic technique to be used by fire protection engineers in the design and analysis of detection and alarm systems. The majority of discussion is directed toward systems used in buildings. However, many of the techniques and procedures also apply to systems used to protect planes, ships, outside storage yards, and other nonbuilding environments.
Speech Intelligibility Measurements in an Office Building
This study investigates how changes to an emergency voice communication system (EVCS) or the building environment affect speech intelligibility in four spaces of an office building: lobby, stairwell, dining area, and open-floor-plan office space. Effects of additional or alternate speaker locations, floor and wall coverings, and background noise on intelligibility are measured via objective means (i.e., meters that evaluated the speech transmission index (STI) of a test signal broadcast via the EVCS). Current practice recommends measurement spacing that appears to appropriately characterize the single-floor spaces, although changes to the environment can reduce STI measurements by nearly 20%. Several suggestions address concerns of when and where to perform speech intelligibility testing.