The overall goal of this study was to develop an instrumented sphere sensor, Blueberry Impact Record Device (BIRD), to quantitatively measure mechanical impacts endured by each blueberry fruit during the mechanical harvest process. The BIRD system has three components: the sensor (a one-inch sphere) with three single-axis accelerometers for data recording, the interface box to connect the sensor with the computer, and the custom-made computer software developed using LabVIEW to set up the BIRD sensor, download and process the data. The BIRD sensor has been fully calibrated with accuracy of -0.53~0.33% over the range of 500 g and precision error of 0.63%. The BIRD sensor was successfully applied in the field to quantitatively describe what a typical blueberry experiences during the mechanical harvest process. Three major types of blueberry mechanical harvesters (rotary, slapper, sway) were evaluated using the BIRD sensor. The BIRD sensor data were also correlated with the actual bruising rate of blueberries in three cultivars. The BIRD sensor was proven to be an effective sensing device to evaluate blueberry bruising and the performance of mechanical harvesters. The information collected by the BIRD system can be used to improve blueberry mechanical harvesters with reduced blueberry bruising.