Research On Signal Conversion Technology Of Optical Fiber Liquid Level Measurement System

In modern industrial production and daily life, Level measurement technology is widelyused to detect liquid level information.With the rapid development of optical fibercommunication, semiconductor optoelectronics, computers and other high technology, levelmeasurement technology has opened up a new way. Based on optical technology, Fibersensing technique senses signal by fiber and transmits signal by light. After the photoelectricconversion, it’s easy to combine with the rapid development of electronic control systems. Inthis paper, it’s proposed a signal conversion technology of fiber optic liquid level measuringsystem using for the new fiber sensor.In this paper, based on the analysis of level measurement technology development athome and abroad, introduces the new fiber detection principle macrobend level sensor, givesthe overall system design. With the modular design concept, optical fiber liquid levelmeasurement system consists of the light source, level sensors, hardware and software. Ittakes high-power fiber-coupled LED-M660F1produced by thorlabs as the light source,which can provide the system a stable lightwave with wavelength of660nm. It’s discussedphotoelectric detection module, analog to digital signal conversion module, FPGA centralcontrol module, USB data communication module in the chapter of hardware circuit. It’sdiscussed in detail of the photodiode and an operational amplifier noise. In order tooptimization op amp noise performance, the Spice software is used to by simulation differentset of op amp noise. As the central processor FPGA is responsible for AD acquisitionconversion control, FIFO control and USB communication control. PC is responsible forsending commands, analysis and processing of data, drawing data curve and display.Finally, it takes the testing of hardware and software design for signal conversion of optical fiber iquid level measurement system and unctional testing. The results show that thestable performance of the design to meet the design requirements.