Thermal Diffusivity Mapping of Friction Surface Using Photo-Thermal Technique

2000 ◽  
Vol 123 (4) ◽  
pp. 785-790 ◽  
Author(s):  
Kia-Moh Teo ◽  
Khalid Lafdi
Keyword(s):  
Thermal Diffusivity ◽  
Temperature Distribution ◽  
Phase Shift ◽  
Surface Temperature ◽  
Friction Material ◽  
Shift Method ◽  
Surface Temperature Distribution ◽  
Automated Platform ◽  
Thermal Technique ◽  
Phase Shift Method

In this paper, both theory and experimental setup of the photo-thermal technique are presented. Based on this technique, two measurement methodologies are available: phase shift method and temperature change method. However, only the experimental results from the phase shift method are presented in this paper. The measurements can be performed at any radial direction on a sample’s surface. This technique appears to be a successful method for measuring the variation of surface thermal diffusivity of various materials. An automated platform has also been developed and integrated into the technique to measure and map the variation of surface thermal diffusivity of a material. This technique can be used to detect any surface’s thermal defects of a material. It is also useful in studying the surface temperature distribution of a heat application material. One of its applications is on the study of friction. The temperature increase of a friction material subjected to a sliding process is influenced by its thermal property at the sliding interface. The thermal diffusivity mapping of a rubbing surface may help in predicting its surface temperature distribution and in studying the thermal behavior of a friction interface.

Thermal Diffusivity Micro-Measurement Using Photo-Thermal Technique

2003 ◽  
Author(s):  
Khalid Lafdi ◽  
Kia-Moh Teo ◽  
Ahmed ElGafy
Keyword(s):  
Thermal Diffusivity ◽  
Phase Shift ◽  
Radial Direction ◽  
Experimental Setup ◽  
Shift Method ◽  
Surface Temperature Distribution ◽  
Heat Application ◽  
Automated Platform ◽  
Thermal Technique ◽  
Phase Shift Method

In this paper, both theory and experimental setup of the Transmission photo-thermal technique are presented. Based on this technique, two measurement methodologies are available: phase shift method and temperature change method. However, only the experimental results from the phase shift method are presented in this paper. The measurements can be performed at any radial direction on a sample’s surface. This technique appears to be a successful method for measuring the variation of surface thermal diffusivity of various materials. An automated platform has also been developed and integrated into the technique to measure and map the variation of surface thermal diffusivity of a material. This technique can be used to detect any surface’s thermal defects of a material. It is also useful in studying the surface temperature distribution of a heat application material.

A HIGHLY ACCURATE ULTRASONIC MEASUREMENT SYSTEM FOR TREMOR USING BINARY AMPLITUDE-SHIFT-KEYING AND PHASE-SHIFT METHOD

2003 ◽  
Vol 15 (02) ◽  
pp. 61-67 ◽  
Author(s):  
MENG-HSIANG YANG ◽  
K. N. HUANG ◽  
C. F. HUANG ◽  
S. S. HUANG ◽  
M. S. YOUNG
Keyword(s):  
Phase Shift ◽  
Measurement System ◽  
Low Cost ◽  
Phase Shifts ◽  
Ultrasonic Waves ◽  
Shift Method ◽  
Narrow Bandwidth ◽  
Shift Keying ◽  
Modulation Signal ◽  
Phase Shift Method

A highly accurate Binary Amplitude-Shift-Keyed (BASK) ultrasonic tremor measurement system for use in isothermal air is developed. In this paper, we present a simple but efficient algorithm based upon phase shifts generated by three ultrasonic waves of different frequencies. By the proposed method, we can conduct larger range measurement than the phase-shift method and also get higher accuracy compared with the time-of-flight (TOF) method. Our microcomputer-based system includes two important parts. One of which is BASK modulation signal generator. The other is a phase meter designed to record and compute the phase shifts of the three different frequencies and the result motion is then sent to either an LCD for display or a PC for calibration. Experiments are done in the laboratory using BASK modulation for the frequencies of 200 Hz and 1 kHz with a 40 kHz carrier. The measurement accuracy of this measurement system in the reported experiments is within +/- 0.98 mm. The main advantages of this ultrasonic tremor measurement system are high resolution, narrow bandwidth requirement, low cost, and easy to be implemented.

A digital phase shift method for phase compensation of electronic transformer

2017 ◽  
Vol 40 (13) ◽  
pp. 3690-3695 ◽  
Author(s):  
Wei Wei ◽  
Han-miao Cheng ◽  
Fan Li ◽  
Deng-ping Tang ◽  
Shui-bin Xia
Keyword(s):  
Phase Shift ◽  
Phase Error ◽  
Recursion Formula ◽  
Rogowski Coil ◽  
Shift Method ◽  
Electronic Transformer ◽  
Digital Phase ◽  
Fitting Algorithm ◽  
Fixed Phase ◽  
Phase Shift Method

When sampling analog signal, the electronic transformer generally produces a fixed phase error that will compromise the measurement accuracy and require a phase shift method for correction. In this paper, we propose a digital phase shift method based on least squares fitting algorithm and derive the recursion formula of digital phase shift. The simulation has also been done to analysis its performance. The result shows that the method has high phase shift resolution and precision. By applying the method to an electronic transformer based on Rogowski coil, we have experimentally verified the feasibility and validity of the method.

scholarly journals Broiler surface temperature distribution of 42 day old chickens

2010 ◽  
Vol 67 (5) ◽  
pp. 497-502 ◽  
Author(s):  
Irenilza de Alencar Nääs ◽  
Carlos Eduardo Bites Romanini ◽  
Diego Pereira Neves ◽  
Guilherme Rodrigues do Nascimento ◽  
Rimena do Amaral Vercellino
Keyword(s):  
Temperature Distribution ◽  
Surface Temperature ◽  
Air Temperature ◽  
Broiler Chickens ◽  
Broiler Chicken ◽  
Growth Period ◽  
The Body ◽  
Body Parts ◽  
Surface Temperature Distribution ◽  
Thermographic Image

Broiler chickens in Brazil are generally reared from 1 to 42 days when they are exposed to procedures such as fasting, harvesting, crating and transport to slaughter. Maintaining homeostasis is of great importance for broiler survival under harsh environment especially prior to slaughter. Heat loss varies in the distinct parts of the body during the growth period, and it is related to the air temperature of the environment and to the amount of feather covering. This research aimed to study the surface temperature distribution using infrared thermographic image processing to characterize 42 day old broiler chicken surface temperature prior to slaughter. Broilers were reared for 42 days and prior to harvest and transport to slaughter the infrared surface temperature was recorded along the day. Data from the thermograms taken in feather and featherless regions were compared during the 42nd day of growth. High correlation between featherless regions and air temperature was found showing that these areas respond fast to changes in the rearing environment. Two functions were developed for predicting both surface temperature for featherless and feather covered areas of the broiler body parts.

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