Chapter 8Force and TorqueMeasurement of Force/WeightIn-Line (Axial) Load CellLoad Cell Free-Body DiagramLoad Cell Free-Body DiagramLoad Cell Free-Body DiagramLoad Cell Wheatstone BridgeIn-Line (Axial) Load CellIn-Line (Axial) Load CellInterfaceSM SeriesLoad Cell w/Differential AmplifierCantilever Load CellRolling Mill ApplicationPiezoelectric Load CellTorque MeasurementTransducer Techniques Reaction Torque Sensor – TRT SeriesEngine DynamometersHow can you measure motor torque?How can you measure motor torque?Electric Motor DynamometerElectric Motor DynamometerGE Dyno – Torque ArmChapter 8Force and TorqueMeasurement of Force/Weight►Applications ranging from  railway tracks truck vehicles chemical plants food or beverage processing ink or paint mixing load indication in grinding mills web tension measurement on paper machinesIn-Line (Axial) Load CellForceForceForceForceLoad Cell Free-Body DiagramForceForceGage in ______Gage in ______(pure bending)(pure bending)Resistance = _____Resistance = _____ForceForceGage in __________Gage in __________(pure bending)(pure bending)Resistance = _____Resistance = _____Load Cell Free-Body DiagramForceForceWhy is there a hole in the sensor?ForceForceLoad Cell Free-Body DiagramForceForceGage in ______Gage in ______(pure bending)(pure bending)Resistance = _____Resistance = _____Gage in __________Gage in __________(pure bending)(pure bending)Resistance = _____Resistance = _____ForceForceLoad Cell Wheatstone BridgeR+R+∆∆RRR+R+∆∆RRRR--∆∆RRRR--∆∆RR1V2V++VVinin--1V2VIn-Line (Axial) Load CellForceForce“Jumper”wiresForceForceIn-Line (Axial) Load CellForceForceREDGREENWHITEVVininBLACKForceForceInterfaceSM SeriesLoad Cell w/Differential AmplifierGREENRRiiRRffR+R+∆∆RRR+R+∆∆RRRR--∆∆RRRR--∆∆RRVVinin++--REDBLACKWHITERRff--++RRii++VV00--Cantilever Load CellRolling Mill ApplicationUpper RollMetalLower RollPiezoelectric Load Cell►Piezoelectric crystal can be used to directly measure dynamic loads (but not constant loads!) (More when we get to accelerometers.)►“Instrumented” hammer can be used to measure input loads to structures accelerometer measures output from structure FFT/spectrum analysis can be used to experimentally determine transfer functionsTorque Measurement►“torque” wrenches analog digitalTransducer Techniques Reaction Torque Sensor – TRT Series“Reaction Torque” – shaft is not rotatingEngine DynamometersSuperFlow water brakeLoad CellGE DC MotorMoment ArmHow can you measure motor torque?Torque fromMotorMotor is fixedto baseHow can you measure motor torque?PulleyRadius, rWeight, WMotor is fixedto baseElectric Motor DynamometerTorque fromMotorBearingsGenerator isfree to rotateNo load - no torque!Motor is fixedto baseElectric Motor DynamometerL“Torque arm” prevents generator housing from rotatingTorque fromMotorLoadcellmeasures force FFMotor is fixedto baseGE Dyno – Torque ArmL~18