Are strain gage load cells (Weigh Modules) sensitive to temperature?

VPG strain gage load cells are internally temperature compensated to variations in temperature.

The mounting orientation needs to align with the thermal expansion and contraction.

VPG Advanced Sensors Technology strain gages are used in each load transducer and connected in a fully active, four-arm Wheatstone bridge. Precision resistors are added at different locations in the circuitry to compensate for temperature effects. Typical standard compensated values for load transducers are eight parts per million (ppm) per degree Fahrenheit for the output change with temperature and fifteen ppm/ºF for the zero change with temperature. In order to protect the element from the outside environment, the sensing portion of the load transducer is enclosed in a sealed cover. Each load transducer sold by BLH Nobel has special inherent features to protect the sensing element from the effects of side loading.

In its simplest form, a weigh system consists of a vessel whose contents are to be monitored, load cells or weigh modules that generate a signal proportional to the vessel weight, and an electronic device to power, amplify, interpret and display the signal. However, the accuracy of such a system, while obviously a function of the instrumentation, is also dependent upon the vessel design (reactor, batch tank, inventory silo, etc.), support structure, piping attachments, lateral restraint system, vessel environment (temperature, traffic, nearby equipment), and proper selection of transducer accessories. In short, weigh system accuracy is inexorably tied to the degree of attention given to the mechanical details and vessel functionality. High accuracy, process weighing systems exhibit system errors under 0.05% for buy-and-sell to 0.25%. Precision load cells or weigh modules with full temperature compensation must be used.

Load Cell (Weigh Module) Type - BLH Nobel manufactures many types of load cells and weigh modules to suit a variety of applications — general purpose, precision, high temperature, and rugged environment. General-purpose cells/modules are suitable for low accuracy systems; KIS Beams, with tighter accuracy specifications, are intended for high accuracy installations; high-temperature load cells are for use at ambient temperature above 130ºF and incorporate materials that function under continuous elevated temperature operations; ruggedized cells/modules are specially designed for mechanical abuse. Consult BLH Nobel for specific application recommendations.

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