Volume 2, Issue 3 (September 1979)
Suggested Method for the Calibration of Vibrating Tables for Maximum Index Density Testing
The amplitude of vibration of the vibrating table used in the ASTM Test for Relative Density of Cohesionless Soils (D 2049-69) has a significant effect on the value of the maximum index dry density obtained for a particular soil specimen. The table vibration must be calibrated to help ensure conformance with a standard test method. A method for this calibration is given and the required apparatus is described. The results of a sample calibration of an electromagnetic vibrating table are shown both for the maximum amplitude setting of the vibrator power control and for various percentages of maximum power. For a linear decrease in amplitude power control setting, there is a nonlinear decrease in the vibration amplitude of the table. Also shown is a method by which the vibrating table can be checked for the presence of rocking motion in the vibration.