Measuring instrument

摘要

In a measuring instrument (1) for determining the power input and the energy consumption of a consumer of electrical energy, having a measuring sensor (11) which is inserted into the circuit (4) of said instrument, contains a Hall generator (31), and in which a magnetic induction field is generated as a function of the power-determining current, and to which there is connected a voltage-controlled oscillator (14) connected to an arithmetic unit (16), the measuring transducer (11) is provided with a second Hall generator (33) for the purpose of optionally determining all the performance parameters of an AC consumer (3) of the measuring sensor (11) with a second Hall generator (33). The second Hall generator (33) is exposed to the same magnetic field as the first Hall generator (31) and receives a control current which is phase-shifted by means of a phase shifter (35) with respect to the power-determining voltage for determining the reactive power. In addition, the second Hall generator (33) is connected to the arithmetic unit via a further oscillator (24). It is possible in this way to measure the active power and reactive power of the AC consumer (3) and simultaneously to sum up the active-power consumption and energy consumption. These four measurement variables are optionally capable of being displayed. <IMAGE>