A Study Of Rebound Hammer Based On Linear CCD

Rebound hammer is a non-destructive testing instrument of determination of compressive strength of concrete, which is widely used in concrete construction process. It uses the rebound hammer's hammer to impact on the concrete surface. The hammer will rebound a value because of the reaction of concrete surface. The strength of the concrete surface can be obtained on the basis of the relationship between the concrete compressive strength and the value of rebound.Now there are two kinds of rebound hammers that common used in China. One is the pointer to show reading hammer, field testing required manual recording and calculation for the survey area intensity conversion value, which method time-consuming and laborious, and prone to human error. The other uses the contact resistance as the detection device, a voltage across the resistor, using a pointer moving from the spring to obtain the voltage rebound value,but it's short-life, low-accuracy, and poor-applicability.The results of this study is an important part of "smart concrete compressive strength testing system", which is the focus of scientific research projects in Anhui Province Education Department. Through the analysis of domestic and foreign products relatively Hammer and the pros and cons of rebound hammer in current market, according to the detection principle of rebound hammer, using linear array CCD to get the Hammer slider location information. According to the traits of CCD, this paper dedicates to the design of linear CCD Intelligent Detection System. Take sensor technology, intelligent technology and single chip combined to achieve a non-contact non-destructive detection.The system uses XC95144 chip to produce pulse signals to drive CCD chip. After the completion of amplifying and filtering the CCD video original signal, take the signal into the A/D converter. Single chip can get the slider displacement information (the rebound value) through the analysis of the digital quantity that converted by A/D. At the same time send the rebound value to upper computer system by the wireless transmission module. Upper computer data processing system mainly complete the reception of on-site testing data, then dispose and analyse on-site testing data according to the national standards, and finally output a assessment results.Experiments show that the system has the advantage of simple hardware structure,convenient usage, good anti-interference , reliable collection data and so on.