Sensors are an increasing presence in our lives—from wearable gadgets to smart buildings, from autonomous vehicles to smart cities. In occupational health and safety, sensors are used widely for exposure monitoring, emergency response, and safer worker-machine interfaces. The use of sensors as real-time respirable dust monitors is a targeted application with its own specific challenges. The information from real-time respirable dust monitors can be used to identify tasks and activities throughout the workday, during which the worker might be exposed to higher than average concentration levels. The monitors can assess the efficacy and efficiency of engineering control technologies and work practices. In the future, dust sensors might be employed for smart adjustments of control technologies. The first real-time dust monitors used in occupational environments were bulky, complicated to use, and with limited functionalities. Since then, these monitors have become small enough for personal monitoring, with advanced displays and software, and in some cases are capable of transferring and sharing data in real time via Bluetooth and cloud technology. As their popularity increases, it is important to understand how well these monitors perform.
While each commercially available real-time respirable dust monitor might have specialized features, there are three common components: a size selector, a sensing element, and an optional filter media. When using a respirable dust monitor, the operator is sure to focus on respirable dust by the presence of a proper size selector, a cyclone, or an impactor stage. The flowrate at which the respirable dust monitor is used is critical and specific for each size selector type.