Development of a Depth Sensing Device and a Utility Software for a Dynamic Penetrometer

Abstract

<p>A system for sensing depth of penetration of a dynamic penetrometer was developed. It contained an ultrasonic<br />distance sensor working together with a microcontroller capable of sensing and recording distance of penetration<br />and field data necessary for the construction of the penetration resistance (PR) profile. The system was equipped<br />to the conventional dynamic penetrometer of the Department of Soil Science, Kasetsart University at<br />Kampangsan. The depth sensing system was found to work properly. Depth validation by means of t-test yielded<br />t value of 0.1713 as compared to 0.9800 of t-table under two-tailed test. In addition the RMSE and the MAPE<br />values were 1.2625 and 3.3473 %, respectively. Validation test on depth of penetration showed satisfactorily<br />insignificant difference between depths read by the invented device and by standard measurement. A computer<br />program for manipulating field data for PR calculation was constructed. The program was written in Microsoft<br />Visual Basic and imbedded into Microsoft Excel spreadsheet capable of accessing the field data being recorded<br />in an SD card of the ultrasonic distance sensing system. The data was manipulated by means of a user interface<br />that enabled the user to construct the PR profile with ease.</p>