Capacitive level meter for liquid hydrogen

► Capacitive level meter was sensitive, insensitive to magnetic field, and gave no heat. ► The operation was successful using a commercially available AC capacitance bridge. ► The sensitivity of the meter is better than 0.2 mm for liquid hydrogen. ► The meter also worked with pressurized hydrogen. ► Capacitance change by pressure agreed with the change in dielectric constant of hydrogen. A capacitive level meter working at low temperatures was made to use in magnetic refrigerator for hydrogen liquefaction. The liquid level was measured from the capacitance between parallel electrodes immersed in the liquid. The meter was tested for liquid nitrogen, hydrogen, and helium. The operation was successful using an AC capacitance bridge. The estimated sensitivity of the meter is better than 0.2 mm for liquid hydrogen. The meter also worked with pressurized hydrogen.