A screening module 10 comprises a frame component 12 to be secured to an underlying screen deck, in use. In one embodiment, the handle includes a first tube, a second tube connected to a working unit of a portable tool, and wherein a portion of the second tube is telescopically received into the first tube. The total radiation intensity corresponds to a superpositioning of each intensity portion striking the detector for each wavelength; and a signal processing system, which determines for each of the wavelengths the associated intensity portion based on the total radiation intensity measured by detector and the modulations.