In this paper, we present the design and construction of the luminosity monitor, the main features of the detectors, and the functions of the read-out circuits and data acquisition system of the Beijing spectrometer (BES).

• 本文报道了北京谱仪亮度监测器的设计、建造；探测器的性能指标；读出线路及数据获取系统的工作原理.