Front panel for a process controller

摘要

A front display panel for an industrial process control instrument which acts to maintain a process variable, such as flow rate, at a desired value. The instrument compares a signal representing the variable with an adjustable set point to produce an output signal that reflects the deviation of the variable from the set point, the output signal being applied to a final control element such as a valve which governs the process variable. The front panel of the instrument includes a bar graph indicator for the process variable, a bar graph indicator for the set point and a bar graph indicator for the output signal, all three indicators being of the gas discharge type and being integrated into a single panel defining a sealed envelope filled with an ionizable gas and provided with electrodes. Also integrated into the panel are touch-sensitive switches and other control and indicating elements.