By: Michael White

 Definitions 3 Slides  Common Methodologies 7 Slides  Capacitive Pendulum 4 Slides  Works Cited  Questions

 Newton's Third Law  For every action there is an equal and opposite re- action.  Newton’s Second Law  Force = change in momentum with time

 Used for controlling orientation  Requires less thrust than propulsion system

 Strain Gauge  Piezoelectric Sensor

 Uses predictable elastic properties of materials  Change in resistance  Useful for measuring large forces  Commonly used in scales

 Commonly used for more powerful propulsion systems  Difficult to isolate frictional losses and mechanical noise and vibrations

 Material generates an electric potential when a force is applied  Shares the same pitfalls as strain gauge measurement

 Typically optical sensors are used  Uses the principles of Work and Energy

 Difficult to overcome mechanical noise and vibrations as well as frictional losses

 Uses electronic principle of capacitance  Needle point fulcrums eliminate frictional losses  Double pendulum plates eliminate mechanical noise

 Needle point fulcrum  Reduced Contact Area = Reduced Friction  Double Pendulum  Identical pendulums react identically to stimulation

 Generate a mathematical model to define the forces acting on the pendulum  Simple Form  Fg = mg cosΘ  More advanced math required

 Series of amplifiers and filters used to measure the change in signal

    Traceable calibration of the 3-axis thrust vector in the millinewton range, EB Hughes and S Oldfield, National Physical Laboratory  Direct Thrust Measurement of In-FEEP Clusters, IEPC , K. Marhold and M. Tajmar, ARC Seibersdorf research GmbH  Rocket Thrust Measurement For an Estes B6-2 Model Rocket Engine, Peter Hyatt, Jeremy LeFevre, Russell Dibb, Bringham Young University  Thrust stand for ground tests of solid propellant microthrusters, S. Orieux and C. Rossi and D. Esteve, Review of Scientific Instruments, Volume73, Number 7, July 2002  A Ground Test Rocket Thrust Measurement System, Mary Fran Desrochers, Gary W. Olsen, M. K. Hudson, Department of Applied Science and the Graduate Institute of Technology, University of Arkansas  MilliNewton Thrust Stand Calibration Using Electrostatic Fins, Allen H. Yan, Bradley C. Appel, Jacob G. Gedrimas, Purdue University  A Double Pendulum Precision Thrust Measurement Balance, T.F. Yang, Ping Liu, F.R. Chang-Diaz, Harvey Lander, R.A. Childs, H.D. Becker and S.A. Fairfax, Plasma Fusion Center, Massachusetts Institute of Technology