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Applications Note 1-11:FIGURE 1-38. Integral versus Assembled Clamp Structures:Integrally-MachinedClampAccelerationAssembledClampStructureMechanical FrictionDeteriorates HysteresisPerformanceWith reference to Figure 1-37, the location of the strain-sensitive elements oneither side of the transverse neutral axis will result in low differential strains due totransverse bending of the beam, thereby minimizing the transverse sensitivity ofthe beam to transverse inputs. Additionally, the transverse strains that are inducedtend to be self-canceling with proper bridge wiring.Thermal Considerations:Mass MassIf the beam thickness is thin, the thermal tracking from strain gage to straingage is good. When the beam is exceptionally thin, the axial thermalimpedance of the beam is high and a mutual self-heating phenomenon canoccur. The operating heat shed by one strain gage will heat the adjacent andopposite strain gages, contributing to potential thermal instability. In thecase of the fluidically-damped cantilevered-beam accelerometers, thedamping fluid offers a well-coupled and low-thermal-impedance heat-sinkthat reduces self-heating. The self-heating phenomenon, shown in very thinbeam sections, most often occurs in piezoresistive strain-gage installations.The high operating power density and high thermal coefficients of gageresistance (TCR) tend to exacerbate the condition.The Art of Practical and Precise Strain Based Measurement 2nd Edition © 1999 CHAPTER 1-69