Temperature Measurements Using a High-Temperature Blackbody Optical Fiber Thermometer

2003 ◽  
Vol 125 (3) ◽  
pp. 471-477 ◽  
Author(s):  
David G. Barker ◽  
Matthew R. Jones
Keyword(s):  
High Temperature ◽  
Optical Fiber ◽  
Temperature Profile ◽  
Elevated Temperatures ◽  
Short Length ◽  
Experimental Results ◽  
Temperature Measurements ◽  
Spectral Measurements ◽  
Temperature Environment ◽  
High Temperature Environment

A blackbody optical fiber thermometer consists of an optical fiber whose sensing tip is given a metallic coating. The sensing tip of the fiber forms an isothermal cavity and the emission from this cavity is approximately equal to the emission from a blackbody. When a short length of the fiber is exposed to a high temperature environment, the temperature at the sensing tip can be inferred using the standard two-color approach. If, however, more than a short length of the fiber is exposed to elevated temperatures, emission by the fiber will result in erroneous temperature measurements. This paper presents experimental results that show it is possible to use additional spectral measurements to eliminate errors due to emission by the fiber and measure the tip temperature. In addition, the technique described in this paper can be used to obtain an estimate of the temperature profile along the fiber.

Optical fiber sensor cable for pipe thinning detection in high temperature environment conditions

2008 ◽  
Author(s):  
Shimei Tanaka ◽  
Kazunaga Kobayashi ◽  
Tsuyoshi Shimomichi ◽  
Yoshikazu Nomura ◽  
Kinzo Kishida ◽  
...  
Keyword(s):  
High Temperature ◽  
Optical Fiber ◽  
Optical Fiber Sensor ◽  
Fiber Sensor ◽  
Temperature Environment ◽  
High Temperature Environment

scholarly journals Unsteady Pressure Measurement in a High Temperature Environment Using Water Cooled Fast Response Pressure Transducers

1995 ◽  
Author(s):  
D. G. Ferguson ◽  
P. C. Ivey
Keyword(s):  
High Temperature ◽  
Elevated Temperatures ◽  
Thermal Protection ◽  
Dynamic Pressure ◽  
Fast Response ◽  
Ambient Conditions ◽  
Pressure Transducers ◽  
Unsteady Pressure ◽  
Temperature Environment ◽  
High Temperature Environment

Measurement of unsteady pressure is a requirement in many proposed aero-engine active control systems. In the high temperature environment associated with the engine, thermally unprotected transducers may not measure accurately or even survive. This paper reports an examination of two water cooled, commercially available unsteady pressure transducers, which assesses the ability of the transducer to accurately measure unsteady pressure when mounted in a water cooling adapter and the effectiveness of the thermal protection at high temperatures. Mounting the transducer in a cooling adapter was shown to have no adverse effect upon its ability to measure dynamic pressure. Deliberately recessing the adapter back from the flow provided the most stable and predictable output at all flow conditions tested. Thermal protection allowed the transducer to survive at flow temperatures of up to 500°C with a potential to survive at higher temperatures. No reduction in performance is shown at elevated temperatures relative to performance at ambient conditions.

Reconstruction of the Temperature Profile Along an Optical Fiber Thermometer

2001 ◽  
Author(s):  
Matthew R. Jones
Keyword(s):  
Genetic Algorithm ◽  
Optical Fiber ◽  
Temperature Profile ◽  
Inverse Method ◽  
Elevated Temperatures ◽  
Radiative Flux ◽  
Metallic Coating ◽  
Inversion Method ◽  
Spectral Measurements ◽  
Alternative Approach

Abstract A blackbody optical fiber thermometer consists of an optical fiber whose sensing tip is given a metallic coating. The sensing tip of the fiber forms an isothermal cavity, and the emission from this cavity is approximately equal to the emission from a blackbody. Temperature readings are obtained by measuring the spectral radiative flux at the end of the fiber at two wavelengths. The ratio of these measurements is used to infer the temperature at the sensing tip. However, readings from blackbody optical fiber thermometers are corrupted by self-emission when extended portions of the probe are exposed to elevated temperatures. This paper describes an alternative approach for using blackbody optical fiber thermometers that avoids the problems due to self-emission. In the alternative approach, an inverse method incorporating spectral measurements is used to reconstruct the temperature profile along the fiber. A genetic algorithm is used as the basis for the inversion method.

scholarly journals Data Analytics of a Wearable Device for Heat Stroke Detection

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4347 ◽  
Author(s):  
Shih-Sung Lin ◽  
Chien-Wu Lan ◽  
Hao-Yen Hsu ◽  
Sheng-Tao Chen
Keyword(s):  
High Temperature ◽  
High Risk ◽  
Human Body ◽  
Data Analytics ◽  
Heat Stroke ◽  
Physiological Parameters ◽  
Experimental Results ◽  
Temperature Environment ◽  
Great Harm ◽  
High Temperature Environment

When exercising in a high-temperature environment, heat stroke can cause great harm to the human body. However, runners may ignore important physiological warnings and are not usually aware that a heat stroke is occurring. To solve this problem, this study evaluates a runner’s risk of heat stroke injury by using a wearable heat stroke detection device (WHDD), which we developed previously. Furthermore, some filtering algorithms are designed to correct the physiological parameters acquired by the WHDD. To verify the effectiveness of the WHDD and investigate the features of these physiological parameters, several people were chosen to wear the WHDD while conducting the exercise experiment. The experimental results show that the WHDD can identify high-risk trends for heat stroke successfully from runner feedback of the uncomfortable statute and can effectively predict the occurrence of a heat stroke, thus ensuring safety.

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