Products
TML Small Falling Weight Deflectometer System FWD-Light
TML small FWD - Falling Weight Deflectometer - FWD-Light® is used for feat users excellent portability and enables simple and quick measurement of coefficient of subgrade reaction and modulus of subgrade elasticity.
OUTLINE OF SYSTEM
FWD (Falling Weight Deflectometer) is used for estimating construction of pavement or rigidity of subgrade. Also, plate loading test is used for estimating characteristics of subgrade. However, these methods require much time and works for their preparation, data acquisition and analysis. TML small FWD System "FWD-Light" features excellent portability and enables simple and quick measurement of coefficient of subgrade reaction which is called K value and modulus of sbugrade elasiticity which is called E value. FWD-Light consists of main body KFD-100A and indicator TC-351F. The main body includes load cell and acceleration transducer whose measuring ranges are 20kN of load and 2.5mm of displacement at maximum. Values of maximum load and displacement, and analysis results of K value and E value are indicated on the indicator. Each analysis result can be stored in memory card and printed by exclusive printer. Data stored in memory card can be transferred to a personal computer by directly connecting the card or via the indicator. Measurement and processing software TC-7100 is available as an optional item for indicating waveforms of load, acceleration, velocity and displacement, O-P time and time product using personal computer.
System Diagrams
&OUTLINE OF OPERATION
In this system, weight of main body of Small FWD is made to fall freely, and shock load and displacement by the falling are measured by load cell and acceleration transducer. Displacement is obtained by integrating the acceleration twice. Measurement of external displacement of 4 points at maximum is available by combining external displacement sensor KFDS-1B. TML's original process (patent pending) is employed for integraing acceleration data to obtain displacement with high accuracy and good stability. Outputs of load cell and acceleration transducer are digitized by internal A/D converter of Small FWD main body and transmitted to indicator utilizing TML's original 2-wire network technique (patent pending). The indicator indicates results of analyses and also saves them into memory card. Measurement/Analysis software (TC-7100) is required for measurement system with personal computer. In this system, data indicated on the indicator are transferred to the computer through the indicator without modification. Personal computer displays waveforms of load and displacement and also processes each analysis.
