The invention discloses a method for counting foreign matter particles in a
vinyl chloride resin powder comprising the steps of: forming an aqueous
dispersion of the resin particles in a vessel having a transparent bottom,
allowing the particles to settle forming a layer together with the foreign
matter particles and viewing the layer of the deposited particles through
the transparent bottom of the vessel to count the foreign matter particles
in the deposited layer. The invention also provides an apparatus system
for automatically counting foreign matter particles which comprises a
vessel having a transparent bottom, a feed means for the resin powder, a
water supply means, a stirrer means to form an aqueous dispersion in the
vessel, a viewing means such as a CCD camera for recording the bottom
image of the deposited layer through the transparent bottom of the vessel,
and a control means for bringing the various parts of the system into a
sequential linkage motion.
