Fluidic Thermistors or Fluidic Temperature Sensing With Capillaries

1977 ◽  
Vol 99 (3) ◽  
pp. 406-411 ◽  
Author(s):  
T. M. Drzewiecki ◽  
R. M. Phillippi
Keyword(s):  
Experimental Investigation ◽  
Analytical Model ◽  
Dynamic Range ◽  
Temperature Sensors ◽  
Temperature Sensing ◽  
Capillary Temperature ◽  
Sensor Gain

Described in this report is an analytical and experimental investigation of fluidic capillary temperature sensors and subsequent matching to a fluidic laminar gain block. Experimental sensor/gain-block sensitivities of 1.5 kPa/°C were obtained, which compared favorably with the analytical model. Assuming a dynamic range of 104, resolutions of 0.001°C are estimated.

Determination of Thermoacoustic Response in a Demonstrator Gas Turbine Engine

2000 ◽  
Author(s):  
C. A. Arana ◽  
B. Sekar ◽  
M. A. Mawid
Keyword(s):  
Experimental Investigation ◽  
Gas Turbine ◽  
Analytical Model ◽  
Pressure Fluctuations ◽  
Gas Turbine Engine ◽  
Area Ratio ◽  
Fuel Injector ◽  
Acoustic Response ◽  
Turbine Engine ◽  
Discharge Area

This paper describes an analytical and experimental investigation to obtain the thermoacoustic response of a demonstrator gas turbine engine combustor. The combustor acoustic response for two different fuel injector design configurations was measured. It was found that the combustor maximum peak to peak pressure fluctuations were 0.6 psi to 2 psi for configuration A and B respectively. Based on the measured acoustic response, another experimental investigation was conducted to identify the design features in configuration B that caused the increase in the acoustic response. The data showed that by changing the fuel injector swirler’s vane to inner passage discharge area ratio, the engine acoustic response could be lowered to an acceptable level. A simplified analytical model based on the lumped-parameter approach was then developed to investigate the effect of geometrical changes upon the engine response. The analytical model predicted the fuel injector/swirlers acoustic response as a function of the swirlers inner passage discharge area ratio and frequency. The predictions were consistent with the experimental observations, in particular, it was predicted that as the area ratio was increased, the system reactance was decreased and as a result the system changed from a damping to an amplifying system.

scholarly journals Differential Temperature Sensors: Review of Applications in the Test and Characterization of Circuits, Usage and Design Methodology

Sensors ◽  
2019 ◽  
Vol 19 (21) ◽  
pp. 4815 ◽  
Author(s):  
Enrique Barajas ◽  
Xavier Aragones ◽  
Diego Mateo ◽  
Josep Altet
Keyword(s):  
Integrated Circuits ◽  
Analog Circuits ◽  
Temperature Sensor ◽  
Design Methodology ◽  
Dynamic Range ◽  
Simple Procedure ◽  
High Dynamic Range ◽  
Temperature Sensors ◽  
Time Variability ◽  
Linear Power Amplifier

Differential temperature sensors can be placed in integrated circuits to extract a signature of the power dissipated by the adjacent circuit blocks built in the same silicon die. This review paper first discusses the singularity that differential temperature sensors provide with respect to other sensor topologies, with circuit monitoring being their main application. The paper focuses on the monitoring of radio-frequency analog circuits. The strategies to extract the power signature of the monitored circuit are reviewed, and a list of application examples in the domain of test and characterization is provided. As a practical example, we elaborate the design methodology to conceive, step by step, a differential temperature sensor to monitor the aging degradation in a class-A linear power amplifier working in the 2.4 GHz Industrial Scientific Medical—ISM—band. It is discussed how, for this particular application, a sensor with a temperature resolution of 0.02 K and a high dynamic range is required. A circuit solution for this objective is proposed, as well as recommendations for the dimensions and location of the devices that form the temperature sensor. The paper concludes with a description of a simple procedure to monitor time variability.

scholarly journals Textile-Integrated Thermocouples for Temperature Measurement

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 626 ◽  
Author(s):  
Waleri Root ◽  
Thomas Bechtold ◽  
Tung Pham
Keyword(s):  
Output Signal ◽  
Temperature Sensors ◽  
Temperature Sensing ◽  
Temperature Gradients ◽  
Thermoelectric Effects ◽  
Support Materials ◽  
Conductive Materials ◽  
Voltage Output ◽  
Cold Junction ◽  
Polymeric Carbon

The integration of conductive materials in textiles is key for detecting temperature in the wearer´s environment. When integrating sensors into textiles, properties such as their flexibility, handle, and stretch must stay unaffected by the functionalization. Conductive materials are difficult to integrate into textiles, since wires are stiff, and coatings show low adhesion. This work shows that various substrates such as cotton, cellulose, polymeric, carbon, and optical fiber-based textiles are used as support materials for temperature sensors. Suitable measurement principles for use in textiles are based on resistance changes, optical interferences (fiber Bragg grating), or thermoelectric effects. This review deals with developments in the construction of temperature sensors and the production of thermocouples for use in textiles. The operating principle of thermocouples is based on temperature gradients building up between a heated and a cold junction of two conductors, which is converted to a voltage output signal. This work also summarizes integration methods for thermocouples and other temperature-sensing techniques as well as the manufacture of conductive materials in textiles. In addition, textile thermocouples are emphasized as suitable and indispensable elements in sensor concepts for smart textiles.

scholarly journals Flexible Temperature Sensor Integrated with Soft Pneumatic Microactuators for Functional Microfingers

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Satoshi Konishi ◽  
Akiya Hirata
Keyword(s):  
Thin Film ◽  
Temperature Sensor ◽  
Output Voltage ◽  
Temperature Sensors ◽  
Seebeck Effect ◽  
Temperature Sensing ◽  
Bending Test ◽  
Contact Detection ◽  
Dissimilar Metals

Abstract The integration of a flexible temperature sensor with a soft microactuator (a pneumatic balloon actuator) for a functional microfinger is presented herein. A sensor integrated with a microactuator can actively approach a target for contact detection when a distance exists from the target or when the target moves. This paper presents a microfinger with temperature sensing functionality. Moreover, thermocouples, which detect temperature based on the Seebeck effect, are designed for use as flexible temperature sensors. Thermocouples are formed by a pair of dissimilar metals or alloys, such as copper and constantan. Thin-film metals or alloys are patterned and integrated in the microfinger. Two typical thermocouples (K-type and T-type) are designed in this study. A 2.0 mm × 2.0 mm sensing area is designed on the microfinger (3.0 mm × 12 mm × 400 μm). Characterization indicates that the output voltage of the sensor is proportional to temperature, as designed. It is important to guarantee the performance of the sensor against actuation effects. Therefore, in addition to the fundamental characterization of the temperature sensors, the effect of bending deformation on the characteristics of the temperature sensors is examined with a repeated bending test consisting of 1000 cycles.

Experimental Investigation of the Interface between Synthetic and Glass Fibers and Lime-Based Mortars

2016 ◽  
Vol 825 ◽  
pp. 57-62
Author(s):  
Michal Přinosil
Keyword(s):  
Experimental Investigation ◽  
Analytical Model ◽  
Glass Fibers ◽  
Fiber Reinforcement ◽  
Pullout Test ◽  
Theoretical Curve ◽  
Matrix Interface ◽  
The Matrix ◽  
Fiber Matrix Interface ◽  
Displacement Diagram

In this article, the cohesion between fiber reinforcement and lime-based mortar is experimentally investigated using so-called pullout test. The experiment is based on the progressive pulling out of the fiber from the matrix. Comparing the experimental load-displacement diagram with the theoretical curve from the analytical model, the micromechanical parameters describing the fiber-matrix interface are evaluated. In the study, several types of synthetic and glass fibers are considered as well as two types of lime-based mortars. The first one is pure lime, while the second one has lime-metakaolin matrix.

Theoretical and experimental investigation of the thermal resolution and dynamic range of CCD-based thermoreflectance imaging

2007 ◽  
Vol 24 (4) ◽  
pp. 1156 ◽  
Author(s):  
Peter M. Mayer ◽  
Dietrich Lüerßen ◽  
Rajeev J. Ram ◽  
Janice A. Hudgings
Keyword(s):  
Experimental Investigation ◽  
Dynamic Range
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