The Research And Development Of Metal Can Of Dangerous Liquid Detector

With the ever-growing of society and economy, people have a strongerawareness of the safety of public places, which advances the development of securityexpectation equipment and makes more and more researchers working in thedevelopment of dangerous liquid detecting equipment.Many detecting principles are applied in testing the dangerous liquid, includingthe dielectric constant, conductometry, ultra wideband pulse microwave reflection andthermal conductivity etc. The choice of detecting ways is determined by the propertyof the container that holds the liquid. Because the the property of the liquid isdetermined by its thermal conductivity, so, the specific property of the liquid can bejudged by detecting its thermal conductivity, and the non-contact detection of liquidcan be realized. Therefore, the thermal conductivity is a best method to detect theliquid holding in a metal container.Using the thermal conductivity principle, the author of this thesis designed themetal can of dangerous liquid detector, which consist of the sampling module, thecenter microchip for control and processing, POE power-supply, and some relatedsoftwares etc.The main content of this thesis are as follows:1: Based on the characteristic of the property of liquid identified by its thermalconductivity, the author has designed the metal can of dangerous liquid detector andthe detector successfully has detected dangerous liquid.2: The author, after making a study on the principle of thermal conductivity, hasmastered the related knowledge on the heating material and the thermocouple sensor,and has designed a scientific sampling module,which is different from the usualdesign of liquid detector. Using the characteristic of proximity switch, The author hascleverly designed the automatic on-off switch, so that the detector has successfullyachieved the automatic on-off function and has features of intelligence and lowenergy consumption,which made the detector has its own peculiarity.3: According to the practical needs, the author has chosen the C8051F120as the microchip for control and processing of the detection system, and, based on theC805F120, has designed the circuits of the sampling module, including the control,signal process, human-computer interaction, alarm and display.4: Considering the possible working circumstance, the author has designed aPOE power-supply module, which is able to transmit the network data andsimultaneously supply high-power to detector through net cable, under theenvironment of absence of direct power-supply.5: The author has designed two experiments for the detector system: the functionverification of detection, and test of performance index; and the data derived from thetwo experiments has demonstrated that the detector which is designed by author hassuccessfully met the performance requirement.Based on the thermal conductivity, the metal can of dangerous liquiddetector,which is designed by the author of this thesis, has features of fast, sensitive,accurate, safety, stable and well application to a variety of liquid detection holding inmetal cans. This detector can realize the non-contact detection with highefficience,and has great research significance and usefulness.