摘要 |
A device is provided for detection of presence of air within a fluid system containing a dielectric fluid, such as oil. The device comprises a capacitor having a tubular capacitor plate which is connected in series with the fluid system. An elongated cylindrical capacitor plate is coaxially secured within the tube by disc shaped spacers constructed of an electrical insulating material. Both the first and second contacts are connected to an oscillator having a frequency dependent upon the capacitance of the capacitor. The capacitance of the capacitor varies in an amount proportional to the amount of air contained within the dielectric fluid to thereby vary the frequency of the oscillator. The frequency output from the oscillator is connected to an indicator circuit to provide an indication of the oscillator frequency and thus of the amount of air within the dielectric fluid. |