Measurement of Line Distribution of Thermal Contact Resistance Using Microscopic Lock-In Thermography

This paper proposes a new thermal contact resistance measurement method using lock-in thermography. Using the lock-in thermography with an infrared microscope, the local temperature behavior in the frequency domain across the contact interface was visualized in microscale. Additionally, a new thermal contact resistance measurement principle was constructed considering the superimposition of the reflected and transmitted temperature wave at the boundary and taking into account the intensity distribution of the heating laser as the gaussian distribution, and the specific geometrical condition of the laminated plate sample. As a result of the experiments, the one-dimensional distribution of the thermal contact resistance was obtained along the contact interface from the analysis of the phase lag.

Research and Application of Automatic Measurement of Resistance Value Based on a Thermal Control Device

The resistance measurement system of thermal control device is mainly composed of four parts: fixture, interface circuit board, switches module and data acquisition system. The main contents of the system design are as follows: To make the system realize the automatic resistance measurement function of thermocouple, heating belt and heating plate, and improves the measurement speed and robustness of the software; To achieve the friendliness of human-machine interface; At room temperature, it can collect 40 output voltage signals of thermocouple, and judge whether the temperature collection of thermocouple is accurate or not.

Progress and Monitoring Opportunities of Skid Resistance in Road Transport: A Critical Review and Road Sensors

Skid resistance is a significant feature that provides consistent traffic safety management for road pavements. An appropriate level of Skid resistance describes the contribution that the pavement surface makes to tire/road friction, and the surface of the road pavement can reduce vehicle operation cost, traffic accidents, and fatalities, particularly in wet conditions. Wet conditions decrease the level of the skid resistance (pavement friction), and this may lead to serious struggles related to driving on the road pavement (e.g., skidding or hydroplaning), which contributes to higher crash rates. The knowledge of skid resistance is essential to ensure reliable traffic management in transportation systems. Thus, a suitable methodology of skid resistance measurement and the understanding of the characterization of the road pavement are key to allow safe driving conditions. This paper presents a critical review on the current state of the art of the research conducted on skid resistance measurement techniques, taking into account field-based and laboratory-based methodologies, and novel road sensors with regard to various practices of skid resistance, factors influencing the skid resistance, the concept of the minimum skid resistance and thresholds. In conclusion, new trends that are relevant to data collection approaches and innovative procedures to further describe the data treatment are discussed to achieve better understanding, more accurate data interoperability, and proper measurement of skid resistance.