This paper deals with the principle and porformance of thermal demand meters having semiconductor retarding element. The resistance of this semiconductor is very sensitive to temperature. When the semiconductor is heated by electric power in proportion to its load current, the temperature rise of the semiconductor element is proportional to the heating power. The time constant is adjustable by controlling the volume of the semiconductor or the heating method. The compensating method for the change of atmospheric temperature is given by using 2-semiconductor or 4-semiconductor element systems for the measuring circuit. The demand volt-ampere meter has one heating element, while the demand wattmeter has two heating elements. The characteristics of the demand meters are described on various conditions of temperature, power factor, frequency, current and voltage.
信州大学工学部紀要 6: 19-36 (1956)
信州大学工学部紀要 6 19-36, 1956-12-25