Abstract：With three Burris relative gravimeters, we study the effect of feedback scale factor in the meter system on relative gravity observation results. The study indicates there are linear relationships between the feedback scale factor and meter readings of Burris. The larger FBK correlation, the larger change of meter readings, and the positive or negative FBK correlation, determine the direction of gravimeter readings variation as feedback scale factor increases. When the three Burris gravimeters are employed to survey a gravity difference that is 17 mGal between two sites, there are variations of gravity difference, although the changes of feedback scale factor are similar and the largest variation is 0.140 mGal. When one Burris gravimeter is used to measure a gravity difference between two sites, where the FBK correlations are -14.7 mGal and 2.2 mGal, the change of measured gravity difference is larger than 0.300 mGal, if the feedback scale factor changes 2%.