Home arrow Rebar Locator & Bar Sizer
Rebar Locator & bar sizer
Principle & Procedure :
The reinforcement bar is detected by magnetising it and inducing a circulating “ eddy current” in it. After the end of the pulse, the eddy current dies away, creating a weaker magnetic field as an echo of the initial pulse. The strength of the induced field is measured by a search head as it dies away and this signal is processed to give the depth measurement. The eddy current echo is determined by the depth of the bar , the size of bar and the orientation of the bar. This detection of location of reinforcement is required as a pre process for core cutting.
 
Reinforcement Detectors /  Rebar Locators
 
 
Reliability & Limitations :
With this instruments a cover to reinforcement can be measured up to 100 mm with an accuracy of ± 15 % and Manufacturers claim accuracy of a bar diameter measurement with an less than 2 to 3 mm. But it has observed that, most of the available detectors do not accurately measure the bar diameter. Proper calibration of these instruments is very essential.
The factors which affect the accuracy are –
Very closely spaced bars or bundled bars or bars in layers, Binding wire, aggregate containing iron or magnetic properties