基于直角棱镜构成的吸收池用于大气监测光纤气体传感器中,探测光束在吸收池内往返的次数N与过两个直角棱镜各自直角棱的对称面的间距d有关,通过调节间距d实现测量灵敏度的调节.以吸光度差作为输出量,根据其值的不同,选择不同的间距d.在单片机系统控制下,由步进电机实现间距d的自动给定,同时将输出探测光束接收器送到指定位置.采用消色差透镜作为输出光束的接收透镜,则间距d的调节精度对传感器灵敏度设定的影响可不考虑.

Absorption cell based on rectangular prism is used in atmospheric monitor sensor with optical fiber. Times of probing beams propagating back and forth in the cell is determined by distance between symmetry planes through respective apexes of the prisms. The sensitivity of sensor is set by means of adjusting the distance. Taking difference of absorbance for output, the distance is adjusted at different amount of absorbance. The distance is set automatically by step motor under a mono-computer control system, and the receiver of output light beams is moved at corresponding place. An achromatic lens is taken for receiving lens, so that error of adjusting the distance can't affect the setting of sensitivity obviously.