We demonstrate a step change in the capability of diode laser excited two-line atomic fluorescence (TLAF) thermometry and show it is well-suited to the study of low-pressure sooting flames. The new developments to the technique reported here were essential to achieve the accuracy (±41 K) and precision (±8 K) required for useful measurements in such systems. This represents the first application...

BACKGROUND AND PURPOSE Brain temperature is critical for homeostasis, relating intimately to cerebral perfusion and metabolism. Cerebral thermometry is historically challenged by the cost and invasiveness of clinical and laboratory methodologies. We propose the use of noninvasive MR thermometry in patients with cerebrovascular disease, hypothesizing the presence of a measurable brain thermal re...

A novel photoacoustic thermometric method is presented for simultaneously imaging cells and sensing their temperature. With three-seconds-per-frame imaging speed, a temperature resolution of 0.2°C was achieved in a photo-thermal cell heating experiment. Compared to other approaches, the photoacoustic thermometric method has the advantage of not requiring custom-developed temperature-sensitive b...

In optical distance measurements it is essential to know the refractive index of air with high accuracy. Commonly, the refractive index of air is calculated from the properties of the ambient air using either Ciddor or Edlén equations, where the dominant uncertainty component is in most cases air temperature. The method described in this contribution utilizes direct absorption laser spectroscop...

We review the principles, techniques and results from primary acoustic gas thermometry (AGT). Since the establishment of ITS-90, the International Temperature Scale of 1990, spherical and quasi-spherical cavity resonators have been used to realize primary AGT in the temperature range 7 K to 552 K. Throughout the sub-range 90 K < T < 384 K, at least two laboratories measured (T − T90). (Here T i...

This paper presents a state-of-the-art whispering gallery mode (WGM) thermometer system, which could replace platinum resistance thermometers currently used in many industrial applications, thus overcoming some of their well-known limitations and their potential for providing lower measurement uncertainty. The temperature-sensing element is a sapphire-crystal-based whispering gallery mode reson...

THEORY AND FUNDAMENTALS Temperature measurement can be divided into two categories: contact and noncontact. Contact thermocouples, RTDs, and thermometers are the most prevalent in temperature measurement applications. They must contact the target as they measure their own temperature and they are relatively slow responding, but they are inexpensive. Noncontact temperature sensors measure IR ene...