Design of Electrostatic Feedback for an Experiment to Measure <italic>G</italic>
The torsion pendulum at the heart of the apparatus to measure the gravitational constant, <inline-formula> <tex-math notation="LaTeX">$G$ </tex-math></inline-formula> at the Bureau International des Poids et Mesures (BIPM) is used to measure the gravitational torque...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IEEE
2022-01-01
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| Series: | IEEE Open Journal of Instrumentation and Measurement |
| Subjects: | |
| Online Access: | https://ieeexplore.ieee.org/document/9801078/ |
| _version_ | 1797197375071059968 |
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| author | Stephan Schlamminger Leon S. Chao Vincent Lee David B. Newell Clive C. Speake |
| author_facet | Stephan Schlamminger Leon S. Chao Vincent Lee David B. Newell Clive C. Speake |
| author_sort | Stephan Schlamminger |
| collection | DOAJ |
| description | The torsion pendulum at the heart of the apparatus to measure the gravitational constant, <inline-formula> <tex-math notation="LaTeX">$G$ </tex-math></inline-formula> at the Bureau International des Poids et Mesures (BIPM) is used to measure the gravitational torque between source and test-mass assemblies with two methods. In the Cavendish method, the pendulum moves freely. In the electrostatic-servo method, the pendulum is maintained at a constant angle by applying an electrostatic torque equal and opposite to any gravitational torque on the pendulum. The electrostatic torque is generated by a servo. This article describes the design and implementation of this servo at the National Institute of Standards and Technology. We use a digital servo loop with a Kalman filter to achieve measurement performance comparable to the one in an open loop. We show that it is possible to achieve small measurement uncertainty with an experiment that uses three electrodes for feedback control. |
| first_indexed | 2024-04-24T06:42:58Z |
| format | Article |
| id | doaj.art-1a5ef53e23ad4bd5937fd2b8872a4b97 |
| institution | Directory Open Access Journal |
| issn | 2768-7236 |
| language | English |
| last_indexed | 2024-04-24T06:42:58Z |
| publishDate | 2022-01-01 |
| publisher | IEEE |
| record_format | Article |
| series | IEEE Open Journal of Instrumentation and Measurement |
| spelling | doaj.art-1a5ef53e23ad4bd5937fd2b8872a4b972024-04-22T20:23:19ZengIEEEIEEE Open Journal of Instrumentation and Measurement2768-72362022-01-01111010.1109/OJIM.2022.31823919801078Design of Electrostatic Feedback for an Experiment to Measure <italic>G</italic>Stephan Schlamminger0https://orcid.org/0000-0002-9270-4018Leon S. Chao1https://orcid.org/0000-0001-7589-4019Vincent Lee2https://orcid.org/0000-0002-2953-6322David B. Newell3https://orcid.org/0000-0002-2612-1172Clive C. Speake4https://orcid.org/0000-0002-2031-7449Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USAPhysical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USAPhysical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USAPhysical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USASchool of Physics and Astronomy, University of Birmingham, Birmingham, U.K.The torsion pendulum at the heart of the apparatus to measure the gravitational constant, <inline-formula> <tex-math notation="LaTeX">$G$ </tex-math></inline-formula> at the Bureau International des Poids et Mesures (BIPM) is used to measure the gravitational torque between source and test-mass assemblies with two methods. In the Cavendish method, the pendulum moves freely. In the electrostatic-servo method, the pendulum is maintained at a constant angle by applying an electrostatic torque equal and opposite to any gravitational torque on the pendulum. The electrostatic torque is generated by a servo. This article describes the design and implementation of this servo at the National Institute of Standards and Technology. We use a digital servo loop with a Kalman filter to achieve measurement performance comparable to the one in an open loop. We show that it is possible to achieve small measurement uncertainty with an experiment that uses three electrodes for feedback control.https://ieeexplore.ieee.org/document/9801078/Control systemelectrostatic forcesgravitational constantprecision measurementfundamental constantmetrology |
| spellingShingle | Stephan Schlamminger Leon S. Chao Vincent Lee David B. Newell Clive C. Speake Design of Electrostatic Feedback for an Experiment to Measure <italic>G</italic> IEEE Open Journal of Instrumentation and Measurement Control system electrostatic forces gravitational constant precision measurement fundamental constant metrology |
| title | Design of Electrostatic Feedback for an Experiment to Measure <italic>G</italic> |
| title_full | Design of Electrostatic Feedback for an Experiment to Measure <italic>G</italic> |
| title_fullStr | Design of Electrostatic Feedback for an Experiment to Measure <italic>G</italic> |
| title_full_unstemmed | Design of Electrostatic Feedback for an Experiment to Measure <italic>G</italic> |
| title_short | Design of Electrostatic Feedback for an Experiment to Measure <italic>G</italic> |
| title_sort | design of electrostatic feedback for an experiment to measure italic g italic |
| topic | Control system electrostatic forces gravitational constant precision measurement fundamental constant metrology |
| url | https://ieeexplore.ieee.org/document/9801078/ |
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