Abstract: An indicating instrument, for example a temperature controller, which is responsive to a parameter, such as temperature, of an associated system or apparatus comprises a first display arranged in an annular configuration and providing a visual indication of a set-point value of the parameter, a handwheel to adjust the set-point value to a different set-point value, and a second display providing a visual indication of an operating condition of the instrument or of the current value of the parameter. This second display is located within the annulus of the analogue set-point display. Preferably, the second display provides an indication of the difference between the current value of the parameter and the set-point value as shown by the marker. A series of LEDs may be used as the second display.

Abstract: In an instrument assembly (1) a current value indicator element (6) is rotatably mounted on a shaft (5) and a set value indicator element (12) is controlled by a knob (14) and is mounted in the glass face (10) of the instrument for rotation about the axis of the shaft (5). Spur gears (9, 13) connect the set value indicator element (12) to a shaft (8) serving as input to a signal outputting means (7).