LOAD CELLS - THE WAY TO MEASURE THE MECHANICAL VECTOR QUANTITY OF FORCE (F)
Load cells consist of a spring element, which experiences elastic and linear deformation as a result of the force being measured, and a device for measuring this deformation. There are various ways of measuring small deformations. The aim is always to map the mechanical parameter “deformation” onto the electrical parameter “voltage”.
SPRING ELEMENT - the central component
The purpose of the spring element is to absorb the force to be measured and convert it into a uniform strain range. The elastic properties of the spring materials are used to measure the force indirectly. Strain gauges measure the strain on the surface of the spring element. Strain gauges are made of a metal foil rolled onto a substrate. A meandering resistive pattern is etched from this metal foil.
LOAD CELLS - accurate in every situation
Load cells have to cope with a huge range of mechanical conditions. For instance they may have to fit into tight spaces, deliver exceptionally fast readings, withstand off-axis loads, deal with impact loads or track frequent load changes. This is why differently shaped measuring elements are used in the sensors, each possessing specific advantages for their area of use.
STRAIN GAUGES - transform force into signal
Complicated processes are used to apply strain gauges to the surface of the spring element. At burster this is obviously done with the greatest precision and maximum quality, to ensure they are subject to the same deformation as the spring element. When the strain gauges are deformed, they change their length and conductor cross-section. The effect of both is to increase the electrical resistance. This expansion or compression, and hence the force, is measured electrically as a change in resistance.
PRECISION - everything in its place
The design of every measuring element is concerned with providing on the sensor a suitable location on which the strain gauges can be applied. This location must provide enough space to accommodate the strain gauges so that they produce a strain as specified and exhibit absolutely linear and reproducible behaviour.