The electrodes may be in the form of parallel plates or coaxial cylinders to form a convenient portable detector in which case, one of the electrodes may be the wall of the vessel itself.
The electrodes may be in the form of parallel plates. This is to form a convenient portable detector in which case may be the wall of the vessel itself. The electrodes may be in the form of coaxial cylinders. This is to form a convenient portable detector in which case may be the wall of the vessel itself. Case is one of the electrodes.