Measurement of Quenching Layer Thickness by a Thermocouple

Thermocouple Measurement

In 1822, Thomas Seebeck, an Estonian physician, accidentally joined semicircular pieces of bismuth and copper (Figure 1) while studying thermal effects on galvanic arrangements. A nearby compass indicated a magnetic disturbance. Seebeck experimented repeatedly with different metal combinations at various temperatures, noting relative magnetic fi eld strengths. Curiously, he did not believe that...

Electrical measurement of sediment layer thickness under suspension flows

This paper reports a new technique to measure the thickness of a layer of deposited sediment as a function of time, independent of the flow conditions or presence of suspended sediment above the layer. Small electrodes on the bottom and a reference electrode in the fluid above were used to measure the resistance of the layer with a small AC current and a bridge circuit. Using a multiplexer and ...

Measurement of Paint Layer Thickness with Photothermal Infrared Radiometry

Measurement of Meniscal Surface Layer Thickness Using Optical Coherence Tomography

Introduction: With increasing focus on the detection, study and treatment of early stage osteoarthritis (OA), there is increasing interest in novel imaging modalities capable of detecting changes in various joint tissues during early stages of the disease. The surface of the meniscus consists of a relatively thin layer of randomly orientated collagen fibers that overlays the circumferential col...

Transient heat flux measurement using a surface junction thermocouple

A new form of surface junction thermocouple sensor has been developed and tested. The novel feature of the design is the use of a tapered fit between two coaxial thermocouple elements to form a thin, robust junction. The gauge has a response time on the order of 1 ms and is suitable for measuring large transient heat fluxes in hypervelocity wind tunnels. Asymptotic analysis is used to demonstra...