Conventional conveyor weigh scale utilized load cell to convert weigh to resistance, voltage and finally standard signal 4-20 mA before transmitting sit to monitoring and control system. This measurement is contact type measurement method that has potential errors due to wearing, deposit resistant and corrosiveness moreover, the various of tensile strength of conveyor will disturb the accuracy of measurement system. To overcome this problem non-contact weighting scale system should be proposed. In this paper, non-contact weigh scale measurement system based on gamma radiation technique was proposed and implemented. This measurement method consists of gamma ray source 50 mCi, scintillation detector and signal processing. This scales system to weigh the coal transferred from barge to coal bunker Suralaya power plant using belt conveyor. Measurement accuracy of the required scales is Â± 0.5%, while the uptake of gamma radiation by coal on the conveyor belt. Measurements by radiation with an active area of 5 cm x 1.5 meters long. The results show the accuracy of measurement is average of 0.663% compared to Load Cell scales.