Set-up for observation thermal voltage noise and determination of absolute temperature and Boltzmann constant

TL;DR

This paper presents an accessible setup for measuring thermal voltage noise to determine absolute temperature and Boltzmann constant, suitable for educational settings with simple equipment and high accuracy.

Contribution

It introduces a straightforward, educational noise thermometer setup that enables students to measure absolute zero and fundamental constants with minimal equipment.

Findings

Accurate measurement of absolute zero within a week in educational settings.

New method for determining spectral density of operational amplifier noise.

Educational approach suitable for high school and university students.

Abstract

We describe a set-up for measurement of the absolute zero by Johnson-Nyquist thermal noise which can be performed within a week in every high-school or university. Necessary electronic components and technical guidelines for the construction of this noise thermometer are given. The operating temperature used is in the tea cup range from ice to boiling water and in this sense the set-up can be given in the hands of every high school and university physics student. The measurement requires a standard multi-meter with thermocouple and voltage probe and gives excellent for education purposes percent accuracy. The explanation is oriented to university level but due to the simplicity of the explanation motivated high-school students can follow the explanation derivation of the used formulas for determination of the absolute zero and the Boltzmann constant. As a by-product our set-up gives a new method for the determination of the spectral density of the voltage $e_\mathrm{N}$ and current noise $i_\mathrm{N}$ of operational amplifiers.