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REPORT
This report is an archived publication and may contain dated technical, contact, and link information
Publication Number: FHWA-HRT-07-040
Date: October 2011

 

Falling Weight Deflectometer Calibration Center and Operational Improvements: Redevelopment of The Calibration Protocol and Equipment

APPENDIX G. SOFTWARE FLOW CHARTS

The following flow charts show the general outline of WinFWDCal Version 2.0.(11) The Microsoft Visual Basic® source code is available upon request from FHWA or CLRP.

Figure 127. Illustration. WinFWDCal startup flowchart. This diagram shows the startup processes for WinFWDCal. The program initializes the various components of the software and looks for the KUSB data acquisition board. If it finds it, the board is initialized. The first screen of the program is labeled “About” and is shown, and available menu items are activated.

Figure 127. Illustration. WinFWDCal startup flowchart.

Figure 128. Illustration. WinFWDCal start new calibration flowchart. This diagram shows the process when starting a new falling weight deflectometer (FWD) calibration using WinFWDCal. First, the user is asked to read in the FWDCal Center.ini file. If needed, the accelerometer is calibrated, and the calibration center information is approved. Next, the setup of FWD is read into the software. The location for storing the calibration results is then determined. Finally, the trigger levels and drop sequence for reference calibration is determined.

Figure 128. Illustration. WinFWDCal start new calibration flowchart.

Figure 129. Illustration. WinFWDCal open and delete interim calibrations flowchart. This diagram shows the processes used to open or delete interim calibrations with WinFWDCal. To open an interim calibration, the user selects the interim calibration from an available list. The user is asked to confirm which interim calibration will be used, and the software reads the critical data from the stored interim files. To delete an interim calibration, the user selects the interim calibration from an available list. The user is asked to confirm deletion of the interim calibration.

Figure 129. Illustration. WinFWDCal open and delete interim calibrations flowchart.

Figure 130. Illustration. WinFWDCal main menu flowchart. This diagram shows the commands available from the Main Menu screen in WinFWDCal. The menu items available from the main menu are: calibrate accelerometer, edit setup data, calibrate deflection sensors, calibrate load cell, results and certification, monthly calibration, and quit.

Figure 130. Illustration. WinFWDCal main menu flowchart.

Figure 131. Illustration. WinFWDCal calibrate accelerometer flowchart. This diagram shows the process for accelerometer calibration for WinFWDCal. First, the user needs to perform a series of prerequisites if not already done. Then, the software starts the flip calibration. A series of commands are available to start, abort, repeat, accept, or reject the calibration. The user may also go to the main menu. If accepted, the Interim.DDX file is updated, and the user is returned to where he/she came.

Figure 131. Illustration. WinFWDCal calibrate accelerometer flowchart.

Figure 132. Illustration. WinFWDCal edit setup data flowchart. This diagram shows 
the processes for editing the calibration setup data within WinFWDCal. The user can review 
each of the three steps from the initial startup of a new calibration: calibration center information, setup of the falling weight deflectometer, and trigger levels and drop sequence 
for reference calibration.

Figure 132. Illustration. WinFWDCal edit setup data flowchart.

Figure 133. Illustration. WinFWDCal determine trigger and number of drops flowchart. This diagram shows the processes involved in calculating the appropriate trigger and number of drops for falling weight deflectometer (FWD) calibration using WinFWDCal. For the trigger level, the software checks to ensure that the prerequisites are completed. Once completed, the user performs FWD drops as requested, and the software determines the proper trigger level. Command options include: start a drop, calculate the trigger level, accept the trigger level, increase trigger level if an early detection is found, decrease trigger level if a late detection is found, cancel, and return to the main menu. For determining the number of drops, the software checks to ensure that the prerequisites are completed. Once completed, the user performs FWD drops as requested, and the software determines the proper number of drops. Command options include: start a drop, accept the FWD data, cancel, and return to the main menu. In both cases, the Interim.DDX file is updated if the user accepts the results.

Figure 133. Illustration. WinFWDCal determine trigger and number of drops flowchart.

Figure 134. Illustration. WinFWDCal calibrate FWD load cell flowchart. This diagram shows the processes used to calibrate a falling weight deflectometer (FWD) load cell using WinFWDCal. First, the user needs to perform a series of prerequisites if they not already completed. Then, the software starts the trial, and a series of drops are performed. After the drops are complete, the user reads in the data from FWD, and a comparison is made with the reference load cell. A series of commands are available to browse, graph, accept, or reject the data. The user may also go to the main menu. If accepted, the Interim.DDX file is updated, and the user is sent to the next step of the calibration.

Figure 134. Illustration. WinFWDCal calibrate FWD load cell flowchart.

Figure 135. Illustration. WinFWDCal calibrate FWD sensors flowchart. This diagram shows the processes used to calibrate falling weight deflectometer (FWD) deflection sensors using WinFWDCal. First, the user needs to perform a series of prerequisites if they are not already complete. Then, the software starts the reference trial, and a series of drops are performed. After the drops are complete, the user reads in the data from FWD, and a comparison is made with the accelerometer. A series of commands are available to browse, graph, accept, or reject the data. The user may also go to the main menu. If accepted, the Interim.DDX file is updated, and the user is sent to the next step of the calibration. If the next step is relative calibration, the user reads in the data from FWD after performing 40 drops with FWD, and a statistical comparison is made. A series of commands are available to browse for data, show an analysis of variance, accept the data, or reject the data. The user may also go to the main menu. If accepted, the Interim.DDX file is updated, and the user is sent to the next step of the calibration.

Figure 135. Illustration. WinFWDCal calibrate FWD sensors flowchart.

Figure 136. Illustration. WinFWDCal center documentation flowchart. This diagram shows the processes for viewing calibration results, outputting final results, and generating calibration certificate using WinFWDCal. The user gets a chance to review, start, or continue each part of the calibration including: summary, accelerometer, load cell, and deflection sensors. The user can also produce a calibration certificate and report. Once the report is complete, the Interim.DDX file is updated, and the data are stored in a permanent folder. The user may also go to the main menu.

Figure 136. Illustration. WinFWDCal center documentation flowchart.

Figure 137. Illustration. WinFWDCal monthly calibration flowchart. This diagram shows the processes for performing monthly relative calibration and replacing a sensor in the field using WinFWDCal. The user can do a field calibration or replace a sensor. After setting the information about the falling weight deflectometer (FWD) such as the manufacture, sensor type, and the number of sensors, the user is shown instructions for obtaining data from FWD. After, the data are read into the software, and an analysis is performed. A series of commands are available to browse for data, show an analysis of variance, show a relative plot of the data, accept the data, or reject the data. The user may also go to the main menu. If accepted, a series of reports are produced.

Figure 137. Illustration. WinFWDCal monthly calibration flowchart.

Figure 138. Illustration. WinFWDCal search for file and convert to PDDX input flowchart. This diagram shows the process used to determine if the software PDDXConvert should be called from within WinFWDCal. The software calls the program PDDXConvert using a command line option and converts non-pavement deflection data exchange (PDDX) files into PDDX format.

Figure 138. Illustration. WinFWDCal search for file and convert to PDDX input flowchart.

Figure 139. Illustration. WinFWDCal review time history by clicking on drop cell flowchart. This diagram shows the process used to review a time history during a calibration from within WinFWDCal. The user can review any time history from a current reference trial.

Figure 139. Illustration. WinFWDCal review time history by clicking on drop cell flowchart.

Figure 140. Illustration. Quit WinFWDCal flowchart. This diagram shows the process for quitting WinFWDCal. The software updates the calibration center configuration and unloads the forms and data acquisition board.

Figure 140. Illustration. Quit WinFWDCal flowchart.


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The Federal Highway Administration (FHWA) is a part of the U.S. Department of Transportation and is headquartered in Washington, D.C., with field offices across the United States. is a major agency of the U.S. Department of Transportation (DOT). Provide leadership and technology for the delivery of long life pavements that meet our customers needs and are safe, cost effective, and can be effectively maintained. Federal Highway Administration's (FHWA) R&T Web site portal, which provides access to or information about the Agency’s R&T program, projects, partnerships, publications, and results.
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