本文以數位訊號處理器(DSP)為主體設計一訊號量測卡，主要量測感測元(Load Cell)的訊號來架設電子秤，本卡在電路與韌體搭配規劃下，對微小電壓之類比訊號進行取樣，並針對系統選擇適當的工作模式和採樣頻率，以取得系統完整的動態響應，隨後將數位訊號傳回DSP。 接著將所得到的動態響應做系統鑑別，本文以最小平方遞迴法(Recursive Least Square)來求取系統的動態參數，並依所得參數重建系統動態，之後再和原來的訊號做比較，此外，和平均法比較穩定值的預測結果，證明了RLS預測上的效率比平均法好。 In this study DSP play an important role in signal-measure-card designed for the load cell in weighing system. The design in circuit and firmware of this signal-measure-card is focused on measuringmicro-voltage. In order to get a complete dynamic shape, users can instruct DSP to choose proper sampling frequency and gains to resolve analog signals into digital ones. After A/D converting, the data will be transmitted and processed by DSP. Since getting complete information of dynamic, Recursive Least Square is used for system Identification. In this study, the dynamic shape rebuilt by parameter got from system ID is compared with the original dynamic one. Besides, RLS and Mean-method are used for estimating the stable value of weigher, and the result is that RLS is more speedy and useful than Mean-method.