Other metals, such as platinum and gold dispersed in mineral ores in small or trace quantities can also be measured with low energy (less than 80 KeV) XRF, again using the L?? emission bands. [0032] Instead of the arrangements shown in FIGS. 1a and 1 b, the XRF trace element sensor 10 described above can be mounted directly adjacent to a moving stream of material on a conveyor (not shown) using a