User’s Manual to Computer Program CALIBRAT: A Program for Calibration of Nondestructive Testing Devices

Details

• Creators:
  Tandon, Vivek ; Nazarian, Soheil
• Corporate Creators:
  University of Texas at El Paso. Center for Geotechnical and Highway Materials Research
• Corporate Contributors:
  Texas State Department of Highways and Public Transportation
• Subject/TRT Terms:
  Calibration Dynaflect Falling Weight Deflectometers Manuals Nondestructive Tests Sensors Software Testing Equipment
• Publication/ Report Number:
  913-1F, Volume 3
• Resource Type:
  Manual
• Geographical Coverage:
  United States ; Texas
• Edition:
  Volume 3
• Corporate Publisher:
  University of Texas at El Paso. Center for Geotechnical and Highway Materials Research
• Abstract:
  The Falling Weight Deflectometer (FWD) and Dynaflect devices are presently being used by highway agencies. The primary function of the FWD and Dynaflect devices is to measure a deflection basin due to a load imparted to the pavement. Deflection basins measured in the field are used in backcalculating modulus profiles of pavement sections. As such, it is critical to determine the deflection basins in the field with great accuracy. Velocity transducers (also called geophones) are used to determine the deflections, and load cells are utilized to measure applied load. It has become increasingly important in recent years to be able to evaluate the performance of the deflection and load sensors of the Falling Weight Deflectometer or the Dynaflect devices. It has been shown that a small error in the deflection measured in the field may yield significantly erroneous modulus values. As such, a very reliable method for evaluating the accuracy of the sensors used for determining these deflections is necessary. If geophones are used to determine deflections, the algorithm developed for calculating deflection also becomes important. A geophone measures the so-called "raw" particle velocity of the pavement surface directly underneath it. Therefore, the methodology and algorithm employed to obtain the "actual" displacement must be carefully considered. Errors in the load cell measurements are not as important but should be avoided for reliable results. This report contains a user's manual for a computer program called CALI BRAT. The program has been developed to control the acquisition and digitization of sensor's signals, to reduce the collected data, and to present the data. The program is coded for an IBM-PC Compatible equipment with DT 2825 Analog-to- Digital board manufactured by Data Translation, Inc. The program is written in FORTRAN and compiled with MICROSOFT FORTRAN (4.1) Compiler.
• Format:
  PDF
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:4b76c560debd1341bbd0587af11dc72201fa0867347ebe7d57e1f2cdfcc89dd2c993b7422b63206aac45575df6c692c9e5d6ddf15fefa6cd6315f6533d497452
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/86472/dot_86472_DS1.pdf
• File Type:
  [PDF - 596.92 KB ]