А от саме визначення, яке я перекладаю
ISA 5.1 2009 3.1.36 писав:a device used for direct or indirect measurement, monitoring, and/or control of a variable, including primary elements, indicators, controllers, final control elements, computing devices, and electrical devices such as annunciators, switches, and pushbuttons.
a) the term does not apply to a devices internal components or parts, such as receiver bellows or resistors