The Infrared Moisture Device Of Paper By Fiber Sensor

With the development of industry, people care more and more about the quality of the products, which moisture testing on is one of the requirement .In the industry of paper,people always use resistancial or infrared reflectance to detect the moisture content of paper for not destroying the paper. The article provides an infrared moisture device of paper by fiber sensor, which replaces of traditional optical departments and is used for transmitting and receiving signal.This device takes use of double LED and double light ways to detect the moisture content of paper, which separates the signal into detecting signal and reference signal.Divided by these two signals,we can effectively eliminate of disturbance such as the changing power of LED, the bent of optical fiber, rough surface ad so on.The weak signal detected by the photo diode need to be amplified by using the principle of Lock-in amplifier. Analyzing the sampled data ,we can get the monotonous relationship between data and moisture. Thus, we can test the moisture content of unknown paper after those processes. Under the condition of fitting for every quality target, this detector can reduce optics design and improve the quality of the circuit comparatively, retrench the cost sharply.The realization of this instrument can not only be used in moisture testing, but can be applied in other material detecting by using morden spectrum technology when we find the absorbing spectrum and the referencing wavelength of other component. This is the underlying meaning of the topic.