Research On Continuous RF Admittance Instrument

Level measurement and control play an important role in the modern industrial process control, through highly accurate measurement of material level to achieve the right level processing and optimization of process control, and provide the useful information for existing materials storage management. Capacitance level with the advantages of its simple structure, reliable and easy maintenance gets widely used. However, the capacitance level measurement instrumentation in the measurement of conductive adhesive materials for hanging material errors exist, so that capacitive level measurement instrumentation range of applications is subject to certain restrictions; In addition, the instruments on-site inspection in general needed someone to stand guard that is bound to a certain waste of resources; in order to solve these issues, a new type meter that combined the principle of RF admittance and virtual instrument has been designed.Basing on capacitance level measuring method,the paper brought in radio frequency admittance technique to eliminate coating influence. Among them, especially the RF signal generation, filtering circuits, synchronous channel circuit,bridge circuit and the communication interface have been discussed in detail, ADI 12-bit A/D was utilized for converting the analog of level into digital ,using four integrated LED to display real-time Level; the application of stand-alone digital keypad to set the upper and lower limits of level,if more than the value set, then sound and light alarm, using the function keys switch between the current real-time information and level settings.Finally, the work of system's debugging,demarcating and error analyzing were accomplished.This paper used virtual instrument achieving remote level measuring to meet the development trend of detection devices, and created a new measurement pattern, achieved the unattended field testing Level that greatly improved efficiency, reduced labor intensity, so that Level detection work has achieved a new leap forward.