Ch. 8 Switches, Relays, and Alarms Vocab

a switch used to notify an operator when a process variable enters an

abnormal range (e-g, high or low) by triggering an alarm (in the form of a light, a horn, or both), p. 153.

a switch used to actuate a circuit that shuts down a process system or equipment unit, p. 153.

a switch used to override the normal operation of a system or device for equipment startup operations or for routine check of alarms, p. 154.

a device used to determine the velocity, acceleration, displacement, or any combination of these characteristics for the purpose of predicting wear or impending failure. High vibration would activate a switch for an alarm or equipment shutdown, p. 156.

a series of alarms associated with one process unit or equipment system, p. 160.

an electromechanical device that boosts, maintains, or controls the electrical flow of a signal through a separate circuit, p. 158

an electromechanical device used to limit travel of a component beyond a predetermined point, p. 155.

a type of switch that actuates when a predetermined value of a process variable (e.g., pressure, temperature, level, flow, or analytics) is present, p. 156.

an electromechanical device used to limit travel of a component beyond a predetermined point, p. 155.

an electrical device used to start, stop, or otherwise reconfigure the flow of electricity in a circuit, p. 151.