摘要
为实现在恶劣环境下对微小压力变化量的测量,提出了一种基于外差多普勒原理的高精度梁式光纤压力测量系统。通过分析光纤压力测量系统中压力变化量、悬臂梁的形变量、多普勒频移、输出电压四者的关系,建立数学模型。采用差动多普勒测量原理,快速、准确地测量出悬臂梁的形变量,实现对纳米级微小位移的测量。将反射镜位置由悬臂梁中段移至其自由端位置,提高了测量的灵敏度。用光纤准直器代替传统传导光纤,光束的平行度更高,发散角度更小,提高了测量的精度。选用取样积分对有效信号进行提取,结合软件,实现从强噪声信号中提取微弱信号,改善了系统信噪比。实验结果表明,本文提出的光纤压力测量系统的不确定度可达到0.05%,可以实现对缓慢变化的微小压力值的测量,适用于石油、化工等领域。
In order to measure the tiny pressure variation in the harsh environments, a high precision and cantilever beam fiber pressure measurement system based on heterodyne Doppler principle was presented. Through analyzing the relationships of the pressure variation, the deformation of the eantilever beam, the Doppler frequency shif! and the out-put voltage in the optical fiber pressure measurement system,the mathematical model was established. Based on differential Doppler measurement principle, the deformation of cantilever beam could be measured quickly and accurately to realize the displaeement measurement at the nanometer scale. The reflector is moved from the middle of the cantilever beam to its free end ,which improves the sensitivity of the measurement. With optical fiber collimator instead of tradi- tional fiber, the parallelism of the light beam is higher, and the divergence angle is smaller,which improves the accuracy of the measurement. Sampling integrator is selected to extraet effective signal, and combined with the sotfware, weak signals are extracted in strong noise signals, which improves the signal-to-noise of the system. Experimental resuhs show that the uncertainty of the fiber pressure measurement system is less than 0. 05% , and it can realize the measurement of tiny and slow pressure variation. This system is suitable for petroleum and ehemical industry.
出处
《激光与红外》
CAS
CSCD
北大核心
2017年第7期848-852,共5页
Laser & Infrared
关键词
激光技术
压力测量
光纤传导
多普勒效应
差动法
取样积分
不确定度
laser technology
pressure survey
fiber optic transmission
Doppler effect
differential method
sample inte- gral
uneertainty
