Practical Doppler broadening thermometry

Practical, portable temperature sensors drift during use and require periodic calibration against a 'primary' (stand-alone, accurate) thermometer to ensure on-going reliability. Primary thermometers are normally bulky but we aim to develop a portable, optically-based one using Doppler Broadening thermometry (DBT). This provides traceable temperature measurement in-situ in, for example sensor networks, to assure autonomy in a totally new way. This disruptive technology could in future completely change the way temperature traceability is delivered to users, and is aligned with the "Digitisation and Digital NMI" and "Achieving Carbon Net Zero" themes. For "digitisation" DBT will yield temperature traceability at the point of measurement, for "net zero" DBT will improve industrial process control (many of which rely on thermal processing but run sub-optimally due to temperature sensor drift). Solving this issue will optimise, and hence lower, power consumption whilst giving the added benefits of zero waste and consistent product quality. We will establish DBT as a new UK research activity and aim to scale macroscopic DBT approaches (typically 10's cm) to practical sensor size (~cm) using small optical cells filled with atomic and/or molecular species. Our target uncertainty of 50mK in the temperature range 300-500 K, compares well with the precision of competing inexpensive thermocouple and thermistor technologies, but crucially will have absolute accuracy and thereby make an internationally leading contribution.
Veronika's objectives will focus on characterising Doppler broadening thermometry for alkali metal vapours, but with a view to considering other species as well (for different temperature ranges, and potentially lower systematic effects). She will also work more on aspects associated with the miniaturisation of the technology for potential applications.