Canadian Manufacturing

MRO: Hydraulic weighing solution for the heaviest loads

by Lucas Demysh   

MRO Magazine
Manufacturing Operations electrical wiring Hydraulic weighing mechanical force transduce petrochemical tank measurement

Accurately measuring millions of pounds in harsh industrial environments.

Photo: ©️2023 Lucas Demysh. All rights reserved..

Conventional weighing systems used in harsh, heavy industrial applications, such as petrochemical tank measurement and steelmaking processes, have some critical deficiencies.

First, the systems rely on load cells, a type of mechanical force transducer exposed to the rigors of daily operations. As a result, conventional load cells must be overdesigned to meet the anticipated shock loads, sacrificing resolution and accuracy.

Second, conventional load cells require micro-volt sensitive electrical wiring and connections rated for extreme heat, grease, oil, and fluids. To meet safety requirements and maintain reliability, this requires frequent recalibration and unscheduled repairs that disrupt production.

Another significant deficiency with conventional load cells is inaccurate readings. The commissioning calibration of a conventional weighing system processor requires multi-point calibration to formulate a best-fit polynomial that describes the physical characteristics of the multiple load cells working in unison.

If a load cell is stressed beyond its yield point, residual stresses remain, and the original polynomial no longer reflects the new physical characteristics. Unfortunately, multi-point recalibrations are rarely performed in the field, so this frequent error is seldom discovered. In conclusion, all values are incorrect except for the zero and the single point derived from the test weight.

This article originally featured in MRO. Read the full version here.


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