A Guide to the Specification and Procurement of Industrial Process Weighing Systems

Abstract

AGuide to the specification and procurement of industrial process weighing systems U Erdem (Fellow) Deputy Quality Manager, Thameside Maywood Lld www.lnstmc.ol1l.uk Vol3611 febrllllV 2003 Measurement+Confrol 25 www.instrnc.arg.uk Vo136/

Analysis of Belt Weigher Accuracy Limiting Factors

“…In circumstances where significant snowfall or ice accumulation is likely, a protective housing for the load receiver is considered. An accumulation of snow or ice between the load receiver and the supporting structure may cause a force shunting effect, so the use of protective barriers should be considered [20].…”

“…A weighed structure has a natural frequency of vibration related to its mass and the flexibility of its structure. When this structure is disturbed by an imposed vibrating force, it oscillates with a frequency and amplitude dependant on both the parameters of the disturbing force and the natural dynamic characteristics of the weigher system [17,20]. As the measured signal is usually in the lower frequency range, a filter that will effectively cut down noises at the high-frequency end can be designed [10].…”

“…The load receiver and mounting hardware are considered to be such that the maximum impact force does not cause unacceptable long-term damage [20].…”

“…Correct mounting of the belt weigher refers to proper positioning of weigher elements, to mechanical fastening and connecting of weigher elements, according to the technical specifications of the manufacturer, and to the requirements and directions to do with mounting [20,21].…”

“…The calibration shows how the nominal value of the indication of a mass flow relates to the conventional true values of the measurand, realized by a traceable reference standard [15,17,20] under defined conditions and at a specified date and time.…”