Technikatörténeti szemle 9. (1977)

A MÉRÉS ÉS A MÉRTÉK AZ EMBERI MŰVELŐDÉSBEN című konferencián Budapesten 1976. április 27–30-án elhangzott előadások I. rész - Debreczeny Á.–Vajda P.: A Bláthy-féle fogyasztásmérő, az áramfogyasztás gyakorlati mérőmódszerei

The main reason for the introduction of the AC system was the economy in the transmission of electric energy that it achieved. Companies were founded with the objectives of current generation and sales. The Ganz Factory was among the first companies. The Factory began, on concession terms, the construction of electric power plants and the distribution of electric power in several cities in Hungary and abroad. (The main advantage of the AC system lays in the economical trasmission of electric energy to customers far apart and far from the central station.). In the following, a practical problem of high significance, associated with electrical measurements, will be discussed in detail — viz. the watt-hour measurements. This problem Was made timely by the spreading of incandescent lamps and electric motors. Two practical tasks of a business character had to be co-ordinated. On the one hand, it was the interest of the current generating company to measure accurately the electric work (i. e. consumed), in order to make exact record of consumption and accounting. On the other hand, the consumers demanded a measuring instrument that does not drain current itself, thus imposing no load on the power line. Therefore, the current distributing companies issued an invitation for the submission of a device that will measure the current consumption in some way. The invitation specified a broad range; accordingly, widely different types of measuring instruments were marketed. The measurement systems that deserved consideration were based: on the chemical effects of electricity and on the mutual interactions of electromagnetic fields. Accordingly, watt-hour meters may be classified as: 1. chemical (electrolytic) meters; 2. magneto-mechanical meters which may be a) ampere-hour meters b) motor counters c) induction-type meter systems. The electric consumption meters of the time which were suitable for the measurement of DC, were unfit for measuring AC electric power partly because they were based on the chemical effects of electric current, partly because they utilized the interactions between the magnetic field generated by the current and the field of one or several permanent magnets (9). Moreover, those measuring instruments measured only ampere-hours, the product of current and time, not the energy proper. The first attempts to measure the AC current energy applied similar principles. Since, however, they could not measure the AC power in a simple and reliable manner, in most cases a compromise was made concerning the measurement of the duration of energy consumption. Those devices were merely time meters started by the current flowing through them. They stopped as soon as the current consumption was discontinued. In the last decades of the last century, DC and AC watt-hour meters were devised 1880—82 by Edison (10), 1882 by Ayrton and Perry (11), 1882 by de Ferranti and E. Thomson (12), 1884 by Aron (13), 1886 by Werner Siemens (14), 1887 by Hummel (15), — to mention only the major ones.