DIGITAL SIGNAL PROCESSING IN LIQUID LEVELS MEASURING SYSTEM

Rezultat diplomskega dela predstavlja možen način digitalne obdelave analognega signala pri postopku merjenja tekočin z ultrazvočnim merilnim sistemom. Merilni sistem sestavlja ultrazvočni merilnik v navezi z digitalnim signalnim procesorjem (v nadaljevanju DSP, ang. Digital Signal Processing) in namensko razvito programsko opremo. DSP na merilnem vezju izvaja krmiljenje digitalnega sintetizatorja. Ta na osnovi digitalne sinteze, generira analogni signal za potrebe delovanja merilnega vezja. DSP pa je zraven vhoda, priključen tudi na izhod merilnega vezja, kjer z vgrajenim A/D pretvornikom zajema merjeno veličino. To veličino ustrezno obdela in posreduje osebnemu računalniku (PC), kjer so merilni rezultati prikazani s pomočjo namensko razvite programske opreme.The result of our diploma thesis presents a possible method for digital processing an analog signal in liquid measurement process with an ultrasonic measurement system. This measuring system is constituted of an ultrasonic sensor in conjunction with a digital signal processor (DSP - Digital signal processor) and specially designed software. DSP is placed on the measuring circuit to perform controlling of a digital synthesizer. This DSP, which is based on digital synthesis, generates analog signal for operational requirements of the measuring circuit. DSP is as addition to input also connected to the output of measuring circuit, where the measuring variable is covered by built-in A/D converter. This measuring is then appropriately handled and transferred to the personal computer (PC), where the measuring results are displayed by specially developed software