6/6/2011 4:07 PM | |
Posts: 74 Rating: (3) |
Hello hhpp My apologies. I meant to say I understand your comments about the high cost of the test chain... rather than"I understand your comments about the high cost of the belt scale (and storage reel) and the difficulty of doing long material tests." Your data supplied says your Design Belt Speed (P014)is 1.156 m/min. Should this be 1.156 m/sec? The variation in your Rate display from 0 - 45 tph is a concern because this represents 50% of your design capacity. When I see this I would normally suspect a conveyor with substandard idlers, a belt pieced together with old and new pieces and a bad alignment. Amplifying the heck out of the loadcell signals can also do this which can happen when the shipping stops are not released from the scale suspensions. So too, can locatingthe scalein a curve. The repeatability of your tests looks not too bad if I assume the 3998 is in fact 399.Your resolution now is 1/400 but you are only able to achieve 5/400 accuracy.With such a scale, I would expect much better. How are you doing these material tests and are the samples representative of normal loading? Remember, because of (changing) belt tension effects (with loading), a belt scale is linearover the range of.25 to 1.25 of design. The scale should continue to be repeatable but the accuracy at low loading tends to error negative. That is, the scale will weigh light (due to the belt holdingup material). In case you haven't seen this video, it's worthwhile watching. http://www.youtube.com/watch?v=8EXnV8zM88E&feature=channel_video_title As well, our installation guidlines: http://support.automation.siemens.com/WW/view/en/18246952 Cheers [ |:) |
7/4/2011 9:20 PM | |
Posts: 74 Rating: (3) |
Hello hhpp How are you making out on this issue? Toppie |
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