Fast Response Temperature Probes Research Articles

A New Cross-Platform Instrument for Microstructure Turbulence Measurements

This study developed a new cross-platform instrument for microstructure turbulence measurement (CPMTM) and evaluated its performance. The CPMTM is designed as an “all-in-one” payload that can be easily integrated with a variety of marine instrumentation platforms. The sensors in the CPMTM include two shear probes, a fast-response temperature probe, and an accelerometer for monitoring vibrations. In addition, a custom-designed flexible connection vibration-damping device is used to isolate platform vibrations. To validate the CPMTM performance, a direct comparison was carried out with a reference acoustic Doppler velocimeter in a controlled flume for four background turbulence levels. The results of the comparison show that the velocity spectra measured by the CPMTM and ADV w components are in agreement, which demonstrates the ability of the CPMTM to acquire accurate turbulence data. Furthermore, the CPMTM was integrated into the long-range Sea-Whale 2000 AUV and tested in the northern South China Sea in September 2020. The data collected by the CPMTM show that the measured shear spectrum of the noise reduction agrees well with the empirical Nasmyth spectrum. Turbulent kinetic energy dissipation rates as low as 7 × 10−10 W kg−1 can be resolved. Laboratory and field experiments illustrate that the CPMTM has an extraordinarily low noise level and is validated for turbulence measurements.

Measurement of magnetocaloric effect in pulsed magnetic fields with the help of infrared fiber optical temperature sensor

We present a new technique for experimental study of kinetics of phase transitions (PTs) and direct measurement of the magnetocaloric effect (MCE) in pulsed magnetic fields by using the fast response temperature probe with infrared fiber optical (IRFO) sensor. As demonstration of the new technique, the results are presented of MCE measurements for Gd near Curie point: ΔTad = 21.3K under pulsed magnetic field µ0H = 12.7T; and inverse MCE for Fe48Rh52 sample at initial temperature 305.1K: ΔTad = −4.5K under pulsed magnetic field µ0H = 8.5T. Also, the energy losses on magnetization near the 1st order PT were calculated from the results of direct measurements of magnetization versus time for Fe48Rh52 sample: W = 45J/kg.

Thermal product estimation method for aerodynamics experiments

This paper presents an experimental technique to estimate the appropriate thermal product values of rugged and fast response temperature probes (TPs) for hypersonic aerodynamic experiments. Two types of scratches were used, mainly abrasive papers with different grit sizes and scalpel blades with different thicknesses, to form the probe junction. The effect of the scratch technique on the probe’s thermal product is investigated. The probes are tested and calibrated in the test section and in the end wall of shock tube facility. It is observed that the thermal product of a particular TP depends on the Mach number, junction scratch technique, and junction location, as well as on the enthalpy conditions. It is noted that, depending on the scratch technique, some of the TPs do not require individual calibration; however, calibration for others is likely to be needed.

An Inexpensive Thermocouple Probe-Amplifier and its Response to Rapid Temperature Fluctuations in a Mountain Forest

Abstract A sensitive, fast-response temperature probe is important for studying heat flux in the surface layer. This paper describes the construction of an amplifier for use with a fast-response thermocouple probe and presents field data collected with the probe-amplifier assembly. The thermocouple amplifier is based on an Analog Devices AD594CD monolithic thermocouple amplifier with cold junction compensation. The probe uses type E thermocouple wire of extremely small diameter and is available commercially. Laboratory calibration of the amplifier against known temperatures was linear, with a slope new theoretical expectation. The probe amplifier is easy to deploy and responds accurately to rapid temperatures fluctuations. The fine-wire junction is fragile, but inexpensive to repair.