In order to ensure proper operation of crop combine harvesters, the operation should be paused several times during the harvesting, so as to measure grain loss and determine its cause(s). Grain loss depends on combine configurations, material input rate, farm status, and the land conditions. When installed on the back of a combine, “grain loss monitoring” device can determine simultaneous indication of grain loss incurred by the grain separation and cleaning units, while allowing the user to set an optimum progress speed, when moving within the farm, while sticking with an acceptable level of grain loss. Used in this device are highly sensitive piezoelectric sensors. When operating, combine harvester generates such a great deal of vibration which may prevent the sensors from operating properly and reliably. In order to attenuate interferential effects of combine-derived vibrations on the performance of sensors, the vibrations are to be prevented from being transmitted to the grain loss monitoring device, making it necessary to install some vibration absorption mechanism on the combine harvester prior to have the grain loss monitoring device installed. In the present research, not only a vibration absorption mechanism is presented, but also a device is designed and manufactured to evaluate its performance; the complete system is then installed on a combine harvester where it is practically examined. It is observed that the proposed vibration absorption mechanism can absorb nearly all vibrations generated by the combine harvester body, so as to prevent them from reaching highly sensitive sensors with which the grain loss monitoring device is equipped.
