TORSION BALANCE CO.

doi:10.1021/ac60284a797

Determination of the vertical gradients based on Eötvös torsion balance measurements

Pollack Periodica ◽

10.1556/pollack.7.2012.3.11 ◽

2012 ◽

Vol 7 (3) ◽

pp. 109-116 ◽

Cited By ~ 2

Author(s):

Zita Ultmann

Keyword(s):

Torsion Balance ◽

Torsion Balance Measurements ◽

Vertical Gradients

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Cavendish Torsion Balance and Hadron Collider at Cern: Different Fates and Results

10.23959/sfjns-1000010 ◽

2017 ◽

Vol 1 (2) ◽

Author(s):

Khavroshkin OB

Keyword(s):

Hadron Collider ◽

Torsion Balance

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The Torsion Balance Company

Analytical Chemistry ◽

10.1021/ac60276a827 ◽

1969 ◽

Vol 41 (7) ◽

pp. 120A-120A

Keyword(s):

Torsion Balance

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Thermal Noise Decoupling of Micro-Newton Thrust Measured in a Torsion Balance

Symmetry ◽

10.3390/sym13081357 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1357

Author(s):

Linxiao Cong ◽

Jianchao Mu ◽

Qian Liu ◽

Hao Wang ◽

Linlin Wang ◽

...

Keyword(s):

Thermal Noise ◽

Rotation Axis ◽

Electrostatic Force ◽

Thermal Control ◽

Positive Temperature Coefficient ◽

Torsion Balance ◽

Positive Temperature ◽

Thermal Drift ◽

Low Thrust ◽

Z Domain

The space gravitational wave detection and drag free control requires the micro-thruster to have ultra-low thrust noise within 0.1 mHz–0.1 Hz, which brings a great challenge to calibration on the ground because it is impossible to shield any spurious couplings due to the asymmetry of torsion balance. Most thrusters dissipate heat during the test, making the rotation axis tilt and components undergo thermal drift, which is hysteretic and asymmetric for micro-Newton thrust measurement. With reference to LISA’s research and coming up with ideas inspired from proportional-integral-derivative (PID) control and multi-timescale (MTS), this paper proposes to expand the state space of temperature to be applied on the thrust prediction based on fine tree regression (FTR) and to subtract the thermal noise filtered by transfer function fitted with z-domain vector fitting (ZDVF). The results show that thrust variation of diurnal asymmetry in temperature is decoupled from 24 μN/Hz1/2 to 4.9 μN/Hz1/2 at 0.11 mHz. Additionally, 1 μN square wave modulation of electrostatic force is extracted from the ambiguous thermal drift background of positive temperature coefficient (PTC) heater. The PID-FTR validation is performed with experimental data in thermal noise decoupling, which can guide the design of thermal control and be extended to other physical quantities for noise decoupling.

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