Note: Electroless palladium deposits may also contain phosphorus and its contribution to the total phosphorus contentmust be taken into account when reporting the phosphoruscontent of the deposit.The sample to be tested should be flat and ideally not populated with components in the area of measurement. If testingis done on populated boards, consideration has to be given tomeasurement location, such that none of the electronic components block the fluorescent radiation from reaching thedetector, as described in Section 5.4.The test specimen requires no other sample preparation.4 Apparatus An X-ray fluorescence spectrometer consisting of the following:• A radiation source (X-ray tube with adjustable HV powersupply from 10 kV to 50 kV).• A primary beam filter and safety shutter assembly.• A video camera.• An X-ray collimator or a polycapillary X-ray optic.• An energy dispersive Silicon Drift Detector SDD (a device inwhich charge carriers created by the incidence of X-ray photons on a high purity silicon substrate are directed to a measuring electrode by an applied transverse electric field),including electronics.• Evaluation software capable of simultaneously measuringcoating thickness and composition of multiple layers. Thesoftware of the instrument shall have the capability of multiple excitation modes. It is necessary to apply different excitation conditions; a soft excitation for the excitation of P-K at10 kV and a hard excitation for Ni-K at 50 kV.• A programmable X-Y positioning stage (accurate positioningis required especially if small areas are to be analyzed).• The instrument must be able to record the Intensities of theindividual radiation components of the Phosphorous Kenergy line (IP-K) and the Nickel K energy line (INi-K) with sufficient precision.