How often should the calibration of the Pile Driving Analyzer® (PDA) be checked?

The American Society for Testing and Materials (ASTM) Standard D4945 requires that an engineer check the PDA’s internal calibration each testing day. Moreover, PDI recommends that an engineer records a Calibration Test (CT) signal before each test. Following, an engineer can replay the CT to confirm that the PDA.’s internal calibration was correct during testing. More details are available for PDA users who Log In.

If frequent calibration checks are made, as described above, or if a Calibration Box is used because of Piezoresistive (PR) accelerometers, there should be no need for further calibration of the PDA. Nevertheless, further calibration is necessary if the PDA presents questionable measured data. For example, questionable data could be that there is a consistently bad proportionality between force and velocity times impedance at early impact times. Additionally, further calibration is necessary if required by code.

Pile Dynamics recommends the PDA is sent in for recalibration at least once every two years. At that time, the performance of the PDA will be thoroughly checked, upgrades can be made, etc. Please note: Although ASTM D4945 recommends that the PDA be recalibrated at least once every two years, other codes or specifications may have more stringent requirements. In other words, be conscious of each situation’s unique codes or specifications.

ASTM D4945 recommends recalibrating sensors at least every two years.