| 摘要 |
<p>The invention relates to a method and an apparatus for measuring electrical resistivity of the bearing structures made of reinforced concrete, in order to evaluate the degradation condition thereof. According to the invention, the apparatus consists of four co-linear electrodes (E, E, E, E), a module (1) generating sinusoidal constant current, comprising a shunt (3) and a comparator circuit (2), a signal conditioning module (4), a band-pass filter (5), a double alternating rectifier (6), an analogue/digital converter (7), a calibration circuit (8), a displaying device (9), a comparator module (10) and two luminescent diodes (11, 12). As claimed by the invention, the method consists in measuring the concrete resistivity by four electrodes, through the two outer electrodes there is injected a sinusoidal measuring current, with the intensity kept constant by the constant current generator (1), irrespective of the resistivity of the concrete to be measured, and on the two central electrodes there is collected a voltage signal proportional with the resistivity of the concrete to be measured, which, in order to eliminate the errors produced by interference signals, is conditioned and filtered, rectified and measured, and, at the end, displayed, the extreme values of resistivity being signaled.</p> |
