浆氮电容式密度计及液位计的实验研究

Study on the capacitance-type densimeter and liquid level meter for slush nitrogen

采用电容式密度计及液位计来测量浆氮密度及液位的变化,使用整体屏蔽法对测量系统进行保护以减小寄生电容并提高其抗干扰能力。从理论上分析整体屏蔽法在提高测量系统性能上的作用,并通过实验加以验证。在实验中对密度计和液位计进行标定以提高其测量的精度,并使用密度计测量制备过程中浆氮密度的变化情况。

Slush fluid such as slush hydrogen and slush nitrogen is a two -phase single -component cryogenic fluid which contains solid particles in liquid. The capacitance - type densimeter and the liquid level meter are utilized to measure the density and liquid level variation of slush nitrogen. The bulk shielding method based on the double - shielded cables was introduced to reduce the large parasitic capacitance and to improve the anti - interference ability of the measurement system. The performance of the densimeter and the liquid level meter with the bulk shield were analyzed theoretically and validated experimentally. The sensitivities of the densimeter and the liquid level meter were determined respectively by the calibration experiments i＇n order to increase the measurement accuracy. Slush nitrogen was produced by the freeze - thaw method, and the density variation was measured with the capacitance - type densimeter during this period.