A torsional sub-milli-Newton thrust balance based on a spring leaf strain gauge sensor

Area of Science:

• Engineering
• Physics
• Instrumentation

Background:

• Accurate measurement of small forces is crucial in various scientific and engineering fields.
• Existing thrust measurement devices may lack the required sensitivity or resolution for certain applications.

Purpose of the Study:

• To develop and characterize a torsional thrust balance with a spring leaf sensor for high-resolution force measurement.
• To achieve micro-Newton resolution for thrust forces up to 225 mN.

Main Methods:

• Design and implementation of a torsional balance utilizing a strain gauge-based spring leaf sensor.
• Analytical modeling of sensor development and balance dynamics.
• Integration of a passive eddy current damper for motion control.
• Development of an automated calibration system with pulley and weights for atmospheric and in situ calibration.

Main Results:

• The balance demonstrates excellent linearity and repeatability during calibration.
• The sensor achieves a low-noise performance with an estimated resolution of 15 μN.
• A state-of-the-art resolution-to-measurement range ratio was obtained.
• Thrust measurements were successfully performed in the range of 29 μN to 37.04 mN.

Conclusions:

• The developed torsional thrust balance is a capable instrument for sensitive thrust force measurements.
• The system offers high resolution and a wide measurement range, suitable for various applications.
• Further analysis of dynamic behavior may be beneficial to align with analytical predictions.