IEQ Direct Reading Instruments -- Myths and Realities

In this paper various direct reading instruments and techniques used in air monitoring are reviewed. Principles of operation are described, pointing out advantages and disadvantages of using such instruments. A procedure for inspection activities, and a sampling and analysis approach is outlined. One case study, covering inspection in an office space is presented in detail, describing monitoring of different types of contaminants, possible false positives and calculations related to exposure limits. Inconsistencies in design and construction of ventilations systems are also discussed. It was concluded that direct reading instruments used in monitoring of airborne contaminants have improved significantly, presenting improved sensitivity and selectivity, and capable of detecting concentrations below exposure limits in real time. Despite the improved performance of these instruments, integrated sampling, and review of results by experienced specialists may be required to resolve complex IEQ scenarios.