廢水中懸浮顆粒為水處理程序中重要去除對象之一，而為影響處理成效之關鍵，然而因應水中懸浮顆粒性質與入流水水質之變化，沉澱池需即時調整與控制，以維持穩定之出流水水質與處理成效，而現行之沉澱池控制多藉由出流水水質進行回饋控制，而無法即時針對入流水調整適當之水力停留時間，因此本研究發展一量測技術與裝置，針對水中懸浮顆粒之沉澱特性進行量測，提供沉澱池之水力停留時間之控制資訊，並協助發展自動控制；本研究藉由Beer-Lambert定理，使用波長850nm之面光源與液晶螢幕(LCD)，對水樣進行照射，透過量測水樣穿透光與散射光之強度以及其隨沉澱時間之變化情形，於30分鐘之量測時間，計算水中懸浮顆粒之濃度、不同沉澱速度之懸浮顆粒群組與分佈與平均沉澱速度等資訊，沉澱速度最慢可量測至0.01cm/min，並計算其所佔含量，藉瞭解懸浮顆粒沉澱特性，進而推估維持出流水質符合預定標準所需之水力停留時間，使操作人員可藉由量測結果進行沉澱池之調控，並可透過結果所得之資訊評估提昇處理水量或處理效率之可行性，而本量測技術與裝置並可發展為沉澱池入流水之自動監測，進而做為沉澱池自動控制之依據。 Process automation has become one of the most important issues for water and wastewater industry to meet strengthening water quality and effluent standards. While sedimentation is the most common used treatment process in water and wastewater treatment systems, it however is the most difficult one in process automation. This is mainly due to the difficulty in measuring or automatic measuring of the settling characteristics of sludge, flocs or suspended solids. To solve the problem, an innovated real-time measuring technique was developed, with CCD webcam, IR surface light (wavelength 850nm), lcd panel and photo spectrum analysis technique, to measure the concentration, and distribution of settling velocity and their mass of activated sludge, coagulation flocs, or suspended solids of sedimentation tank’s influent, so that the hydraulic retention time required for a specific effluent SS concentration can be obtained with the information measured. A prototype measuring system was built in this study, and was used to measure the settling characteristics of effluents from aeration tank, and flocculation tank of industrial wastewater treatment systems. The results of the prototype system have shown that the settling characteristics were effectively measured. The technique of real-time measuring of sludge settling characteristics was validated with the pilot-scale study.