This paper introduces a new Optical Particle Counter(DLJ-06 OPC) with 90 scattering angle

DLJ-06 OPC is of a LED(ight-emitting diode) as its light source

which has the character of suitable channel and long-use periods. This paper also introduces the principle of the DLJ-06 OPC. The DLJ-06 OPC was used in the experiments conducted at Xiamen for measurement of size distribution. The extinction coefficient and scattering coefficient were computed according to size distribution measured by DLJ-06 OPC were compared with the ones measured by Aethalometre and Integrating Nephelometer(wre designed by TSI). The comparison indicates that the size distribution measured by DLJ-06 OPC are reasonable.