or operation of plants of the same design information for the pre determined mode in the form of a table of program is developed by sensing the operation of related equipment utilized over a period of time in the same manner as the gas cleaning device and or system being controlled for example a similar gas cleaning device and or system may have been monitored over a period of years information with respect to the response of the surfaces depending upon material build up is collected and utilized to formulate a program for controlling like equipment further information previously determined with respect to the operational characteristics of a particular gas cleaning device and or system may be inputted into the controller so that the information with respect to a particular controller may be used as pre determined program information for purposes of controlling the vibration generators used to operate the components of the gas cleaning device and or system it is to be noted that the feedback mode provided that the actual ranges of variation of vibration frequency are broad allows the determination of the resonant frequency f r of each zone i e the frequency for which the amplitude of the resulting vibration is maximum for instance under completely clean conditions.