Time and strain can become evident when a difference is apparent in trolley movement from one side to the other of a multi
When two load cells are utilized to suspend the live rail, they should be able to be matched or tuned to read the same weight indication repeatedly. This should be verified by using certified test weights to check the scale operation on a frequent and recurrent basis. If the weight is not correct from one end to the other, adjustment may be possible at the summing card if weighment error appears consistent. Just as with people, not all parts wear down the same way.
This type of problem could be attributed to simple metal fatigue or electrical properties internally. The good sign, however, is that the apparent problem appears consistent, thus it is possible for it to be corrected by simple adjustment and calibration.
When the weight indication is not consistent and is grossly incorrect on one side as opposed to the other side, a load cell or summing board is most likely at fault. Load cells have an internal strain gauge, and as alluded above, the strain over time can sometimes be fatal, and load cell replacement is required. Maintenance people sometimes check for this situation by testing load cells for correct resistance values. Consistent and large error weight indications across a load cell are often a good indication it’s time for a change. When problems are specific and consistent, they can sometimes be easy to identify and subsequently rectify.