| 摘要 |
An ohmmeter for measuring very low electric resistances, for example the very low resistance of a very high current electric joint, which ohmmeter comprises a source for establishing a measuring current through the joint to thereby create a voltage drop proportional to the magnitude of the measuring current and to the resistance to be measured. A first integrator integrates a signal respresentative of the magnitude of the measuring current in order to produce a first integration signal, while a second integrator integrates the voltage drop proportional to the measuring current and to the very low resistance in order to produce a second integration signal. The two integrators are simultaneously reset to zero so that they both start their respective integrations at a same instant. The first integration signal is compared to a reference signal through a comparator. When the amplitude of the first integration signal reaches the amplitude of the reference signal, the comparator delivers a signal which stops the integration carried out by the second integrator. The second integration signal is then stored, this signal having an amplitude constituting a measure of the very low electric resistance. A display device receives the stored integration signal for displaying the value of the measured resistance.
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