Research On Key Techniques Of Moisture Analyzer

Moisture content impacts on product’s characters, storage, transportation and energy consumption. As a technique innovation for determination of moisture content, electronic moisture analyzers work automatically under the command of microcontroller so that users can operate them easily and get the moisture content in a few minutes.Currently, some electronic moisture analyzers in the domestic market work poor on key techniques and operability. Most products are produced with the old national institute of standards, so they can not meet the new standards released in 2010 and can not ensure the measurement accuracy. Some electronic moisture analyzers can not work well on display with so less necessary information on it. Even some custom code is designed for users to operate. Also, the huge appearance is another inadequacy of these products. Drying box can not perform well on temperature control, causing low control accuracy, large overshoot and long constant temperature settling time. Sensitivity and stability can not be guaranteed, so weighing performance needs to be improved. When working under high temperature for a long time, weighing sensor’s creep and poor performance may affect the weighing accuracy seriously. Due to long measurement time and low accuracy, custom drying method is not conductive to fast determination of moisture.In order to improve the current situation of electronic moisture analyzer, this thesis designs a kind of fast moisture analyzer which works under maximum weighing 200g and minimum scale 1mg, based on the new national institute of standards. Firstly, put forward the importance of moisture determination and outline some currently popular moisture determination methods. Secondly, give brief introduction of the measuring principle and system components of the moisture analyzer, then determine the accuracy level of it basing on our national accreditation standards. Thirdly, highlight key techniques about drying box fuzzy PID temperature control and weight signal processing, including hardware basement, software algorithm and specific implementation process. Simulations and experiments are selected to test and verify the accuracy and reliability of each function module. Last, do some performance tests on this instrument based on the testing standards of moisture analyzer and electronic balance.The moisture analyzer works under stable performance and accurate measurement. The software of this instrument has so many highlights such as friendly interface, simple operation, high degree of automation, remote-operated and various functions. With these features, the instrument can be applied to various areas and provides automatic and fast moisture analyzing. Experiments show that this fast moisture analyzer meets the new standards and work well in solid or liquid sample measurement within the scope of the error.