30 November 1998
A device that linearly converts a 4 to 20
milliampere input signal to an output signal of
20 to 4 milliamperes.
A device that selects the highest or the
lowest of its input signals as its output signal.
Single Loop Digital Controller - A controller
that accepts analog input signals, processes
the signals digitally according to the
controller configuration, and, as a result,
produces analog output and two-position
A generic term for devices that are used to
operate safety circuits on the detection of
The number of engineering units between
The range over which the input signal to a
controlled device must change to move the
device from one extreme to the other.
A device installed outdoors on the surface of
a building to house outside-air
temperature-sensing elements and to shield
them from direct exposure to sun's radiation.
Gauge pressure of the compressed air
supplied to a pneumatic control system,
usually 140 kPa (20 psig).
Voltage of the electric energy supply to an
electric/electronic control system.