  The Active Particle-induced X-ray Spectrometer (APXS) is one of the payloads
on board the Yutu rover of Chang'E-3 mission. In order to assess the
instrumental performance of APXS, a ground verification test was done for two
unknown samples (basaltic rock, mixed powder sample). In this paper, the
details of the experiment configurations and data analysis method are
presented. The results show that the elemental abundance of major elements can
be well determined by the APXS with relative deviations < 15 wt. % (detection
distance = 30 mm, acquisition time = 30 min). The derived detection limit of
each major element is inversely proportional to acquisition time and directly
proportional to detection distance, suggesting that the appropriate distance
should be < 50mm.
