A method for dispensing a chemical solution in the small-scale manufacture of semiconductors is provided. The assembly includes a cylindrical mandrel rotatably mounted to a clamping bracket. The vibrator device is operative to remove accumulated deposits from the spray dryer absorber and its components, such as its dispersers and atomizers, to avoid spray dryer absorber performance interference caused by such deposit accumulations. With this arrangement, it is possible to compensate the delay of the transmission delay time and display the images at a timing synchronized with the timing of outputting the sounds. The measuring circuit is configured to measure a mean value of the excitation current in the secondary coil and determine therefrom a value of the primary current for small current amplitudes, the measuring circuit being further configured for evaluating the frequency of the excitation current i and determining therefrom the value of the primary current for large currents.