Practical primary thermometry via alkali-metal-vapour Doppler broadening
Abstract
Doppler-broadening thermometry (DBT) can be used as a calibration-free primary thermometer suitable for practical applications, e.g. reliably measuring temperatures over long periods of time in environments where sensor retrieval for recalibration is impractical. We report on our proof-of-concept investigations into DBT with alkali-metal-vapour cells, with a particular focus on both absorption and frequency accuracy during scans. We reach sub-kelvin temperature accuracy, and experimental absorption-fit residuals below 0.05%, in a simple set-up. The outlook for portable, practical devices is bright, with clear prospects for future improvement. This article is part of the Theo Murphy meeting issue 'The redefined kelvin: progress and prospects'.
Fields of Study & Subjects
Calibration and Measurement Techniques
Chemical Thermodynamics and Molecular Structure
Atmospheric Ozone and Climate
Publication details
- Journal / source
- Philosophical Transactions of the Royal Society A Mathematical Physical and Engineering Sciences
- Publisher
- The Royal Society
- Volume
- 384
- Issue
- 2312
- Publication date
- 15 January 2026
- Language
- EN