A non-linearity with respect to the ideal response exists in a belt scale application with design rate of 200 t/h. It is decided to do material tests at 25, 50 and 75% of the design rate. After performing a zero and a span calibration at 100% of the design rate, followed by material tests and manual span adjust, three material tests were performed at 50, 100 and 150 t/h, as indicated by the BW100. The following data was tabulated. (This example is exaggerated for emphasis). Example: The material tests should be run at same belt speed, representative of normal operation; in this case 1.2 m/s.
For each rate, record the corresponding load value by scrolling to the BW100 load display during running conditions or by calculation. load = rate speed *calculation example: % compensation = 4.2 - 4.9 x 100 4.9 = - 14.3 20 actual weight per material test totalized weight by BW100 belt scale response linearized BW100 response % compensation span (100%) 15 weight = tonnes -8.0 10 10.5 5 -14.0 3 Recalibration 0 10 20 30 40 50 load - kg / m Page 40 Milltronics BW100 - INSTRUCTION MANUAL 7ML19985DJ01 BW100 load kg/m material test tonnes BW100 total tonnes compensation* % 11.6 4.2 4.9 -14.3 23.2 8.4 7.6 10.5 34.7 12.6 13.7 -8.0