Àü±âÀüµµµµ¿¡ 0.5À» °öÇϸé Dissolved Solid ( ppm as CaCO©ý)¿¡ ÇØ´çÇÑ´Ù. ¿¹) 0.5 us/cm- ¡¿ 0.5 = ppm as CaCO©ý