新型射频电容式物位测量仪

摘要

为了测量具有不同导电性物料的高度、提高物位测量仪的抗干扰能力和测量精度,设计了一种单电极、两线制射频电容式物位测量仪.该测量仪基于电容充放电原理,以射频信号为激励,通过电容式传感器测量物位高度；采用差分补偿电容技术,有效地消除了寄生电容的影响；采用光耦隔离测量回路和控制回路,提高了电路的抗干扰能力.实测数据表明,所设计的电容式物位测量仪具有抗干扰能力强、稳定性好的特点.应用前景广泛.%To measure the height of level for materials with different conductivity and enhance the measurement accuracy and anti-interference capability of the instrument, the single electrode, two-wire radio frequency capacitance material level measurement instrument has been designed. Based on the principle of charging and discharging of the capacitor, and with the RF signal as energizer, the height of material level is measured via capacitance sensor. Through using differential compensation capacitance technology, the influence of parasitic capacitance is eliminated effectively; and by adopting optical coupling measuring loop, the anti-interference capability of the circuit is enhanced. The test data show that this instrument features high capability of anti-interference, good stability and possess wide applicable prospects.