ESD continuous (or constant) workstation monitors are used to monitor the buildup of electrostatic energy in workstations, primarily between a worker and equipment. Monitors are plugged into both the worker's ESD wrist strap and the workbench or mat. Units grounded by an AC adapter constantly measure the environment for electrostatic energy and provide a readout of results. Some monitors emit a green light when conditions are safe and red when conditions are unsafe. Some monitors have a visual alarm.