利用低温液体的介电常数与其蒸气介电常数不同,用一个同轴管电容器作为液面的敏感元件,当两管之间的环形空间中液面升降时,探测电容值就发生变化。探测电容作为交流电桥的一个臂,交流电桥输出的不平衡讯号经放大,检波,整流,最后由电表指示。低温液面 The use of low temperature liquid dielectric constant and its vapor dielectric constant is different, with a coaxial tube capacitor as the liquid level of the sensing element, when the liquid level in the annular space between the two tube rises and falls, the detection capacitance changes. Detection capacitor as an AC bridge arm, AC bridge output of the unbalanced signal amplified, detection, rectification, and finally by the meter instructions. Low temperature surface