With the ability to operate as a standalone system or be integrated with a building automation system, the MatrixMonitor™ is a digital instrument that gauges airflow in fan arrays containing three to 98 fans, with maximum airflow of 300,000 cfm per array. The instrument consists of sensors and internal wiring for each fan connected to an embedded processor. The system, which operates on a 100-W power supply, generates one airflow signal for an entire fan array rather than individual signals for each fan. According to the manufacturer, with MatrixMonitor, the multiple fans in a fan array are monitored as if they were a single fan. When a customer adds plenum fans to a system, the instrument can easily accommodate the new equipment. Four scalable output signals of 0-10V are used to communicate the airflow and array pressure rise in separate fan arrays. The system alerts users to any problems with a particular fan or an array. Such information, along with other data related to performance and operational status, is available in real time on the two-wire multidrop RS485 communication line using the Modbus protocol.