This paper presents a review of direct-reading aerosol instruments available to occupational health and safety professionals, describes the principles of operation, guides instrument selection based on the workplace and exposure, and discusses data analysis techniques to. This paper presents a review of direct-reading aerosol instruments available to occupational health and safety professionals, describes the principles of operation, guides instrument selection based on the workplace and exposure, and discusses data analysis techniques to. Direct-reading instruments are valuable tools for detecting and measuring worker exposure to gases, vapors, aerosols, and fine particulates suspended in air. These instruments permit real-time or near real-time measurements, and their use is specifically required by some OSHA standards. However, real-time monitoring, using portable direct reading equipment, can be extremely helpful at determining the 'where and. The Center for Direct Reading and Sensor Technologies (CDRST) was established in 2014. This includes the NIOSH Mining program, the NIOSH Oil and Gas program, the National Occupational Research Agenda Manufacturing Sector Council, the NIOSH. This guideline provides a uniform and practical means for validating direct-reading monitor methods for workplace exposure of hazardous chemicals by the Occupational Safety and Heath Administration's (OSHA) Salt Lake Technical Center (SLTC). It defines required laboratory tests and statistical. Direct read instruments for chemical contaminants identify and/or quantify the concentration of many gases, vapors, and particulates in air -- in real time or near real time. An. Occupational health and safety (OHS) professionals have a new resource now to help them select and operate direct reading instruments (DRIs) and their sensor components: on May 26, 2020, the AIHA volunteer workgroup completed the “Guidance on Use of Direct Reading Instruments” draft document and.