A Low-Noise High-Resolution Temperature Measurement Technique Based on Inductive Voltage Divider and...

Area of Science:

• Physics
• Astrophysics
• Instrumentation

Background:

• Space gravitational wave detection demands micro-Kelvin temperature resolution in the milli-Hertz range.
• Temperature fluctuations pose significant interference to sensitive core components.
• Conventional methods struggle with resistance thermal noise and electronic 1/f noise.

Purpose of the Study:

• To develop a low-noise, high-resolution temperature measurement method for space gravitational wave detection.
• To overcome limitations of existing techniques in mitigating thermal and electronic noise.
• To achieve micro-Kelvin level temperature resolution in the milli-Hertz frequency range.

Main Methods:

• Utilizes an inductive voltage divider and an alternating-current (AC) bridge for temperature sensing.
• Employs AC excitation signals to circumvent 1/f noise from electronic components.
• Minimizes resistance components in the AC bridge and detection circuit to reduce thermal noise.
• Applies a frequency-domain data processing algorithm based on discrete Fourier transform for enhanced accuracy.

Main Results:

• A prototype circuit board was designed and tested.
• The developed temperature measurement circuit achieved a noise floor below 7×10-6 K/Hz.
• Effective measurement was demonstrated within the 0.005~1 Hz frequency range.

Conclusions:

• The proposed method successfully achieves micro-Kelvin temperature resolution.
• It effectively mitigates noise sources critical for space gravitational wave detection.
• The technique meets the demanding temperature measurement requirements for this field.