elektriline kompareeriv mõõtesüsteem elektriliste suuruste täpseks mõõtmiseks, four-arm measuring bridge intended to measure the value of a resistor which forms one of the arms, the other three arms being resistors, at least one of which is adjustable, six-arm measuring bridge intended to measure the value of a four-terminal resistor by comparison with a four-terminal standard resistor, all of the arms being resistors, at least one of which is adjustable, alternating current measuring bridge intended to measure impedances, in which at least two arms consist of tapped windings on a transformer, making use of the known ratios of the turns and which can therefore have fixed-value standards