Study Of Paper Moisture & Weight Testing Techniques Based On Near-infrared Radio

Near-infrared Radio (NIR) measurement method is a kind of green testing technology, which can detect the multi-component at the same time. In this thesis, for the purpose of paper moisture&weight online non-destructive testing, the NIR paper moisture&weight online testing techniques are studied.By broadly nvestigating literatures about NIR, the paper moisture and weight testing theory based on NIR, the instrument design and the real-time monitoring software development are studied systematically through theorical and experimental researches. The main works are as follow:(1) The necessity and urgency of the NIR paper moisture&weight online testing is described, Moreover, the basic concept, system composition, testing method and research situation of the NIR paper moisture&weight online testing techniques are also introduced in this thesis.(2) The paper characteristics, moisture sensors, the key technology of NIR moisture&weight testing are analysed. On the basis of the above work, an overall framework of the NIR moisture&weight testing system is put forward.(3) In order to measure paper moisture&weight accurately, 4 model methods, the first oder linear fitting and the quadratic curve fitting in a least-squares sense, Multivariate Linear Models and BP neural network, are applied according to the transmission characteristics of the moisture&weight testing in the NIR paper moisture&weight testing. And moisture&weight mathematical models are set up for several different kind of paper. On the other hand, prediction errors are discussed by using the above models. The analysis result shows that the BP model has high accuracy in paper moisture&weight testing, the model also has ability of overcoming the nonlinearity influence of moisture, filler and fiber.(4) In order to implement the purpose of all-in-one instrument and online moniroting of moisture&weight, the principle of the NIR paper moisture&weight testing instrument, data acquisition and processing are studied, and a real-time monitoring software and database manage system of host computer are developed. By devloping a serial communication procedure, the host computer and the NIR paper moisture&weight testing instrument can communicated each other, this makes monitoring both weight and moisture parameter of paper online with only one system. The mode of the system changes the traditional testing mode which measures the paper weight and moisture parameters by using 2 separate instruments, it reduces the cost of the testing system and the operation procedure is also simplified.