Abstract: An alternating current power measuring apparatus includes a first capacitance element having one end connected to a conductor wire of a first electrical cable of a set of electrical cables for supplying alternating current to a load and having the other end capacitively coupled to a conductor wire of a second electrical cable, a first voltage measuring part which measures a first voltage which is a voltage of both ends of the first capacitance element, a first current measuring part which measures a first current flowing in the first electrical cable, and a processing part which computes a power to be supplied to the load by the set of electrical cables by the multiplication among a proportion between a specified voltage value of a voltage applied to the set of electrical cables and an effective value of the first voltage, the first voltage and the first current.

Abstract: An alternating current power measuring apparatus includes a first capacitance element having one end connected to a conductor wire of a first electrical cable of a set of electrical cables for supplying alternating current to a load and having the other end capacitively coupled to a conductor wire of a second electrical cable, a first voltage measuring part which measures a first voltage which is a voltage of both ends of the first capacitance element, a first current measuring part which measures a first current flowing in the first electrical cable, and a processing part which computes a power to be supplied to the load by the set of electrical cables by the multiplication among a proportion between a specified voltage value of a voltage applied to the set of electrical cables and an effective value of the first voltage, the first voltage and the first current.

Abstract: To miniaturize a secondary-electron detector, a ring-shaped secondary-electron emissive material layer 44A is formed on a ring-shaped base 41 having a round hole 41a, via a ring-shaped insulating layer 42A and a ring-shaped high resistance layer 43A. Similarly, a ring-shaped secondary-electron emissive material layer 44B is formed on a ring-shaped base 33 having a round hole 33a, via a ring-shaped insulating layer 42B and a ring-shaped high resistance layer 43B. A arc-shaped multiplied-electron collecting electrode 461 is joined between the insulating layers 42A and 42B outside the secondary-electron emissive material layer 44B. A porous secondary-electron multiplication substance may be filled between opposed bases instead of the secondary-electron emissive material layers 44A and 44B, and an optical fiber coated with phosphor may be used instead of the electrode 461.