Sensors bimetallic

The second control rod system foreseen in the MARS reactor is a passive type and causes control rods insertion into the core when the core coolant temperature reaches a selected set value. The operation of this system (called ATSS, Figure IV-6) is based on the differential thermal expansion of a bimetallic sensor located inside the fuel assembly the differential displacement, due to coolant temperature increase, causes the release of a traditional-type control rod cluster. 

Verifying temperature is the second most important aspect of any compressor operation. As with pressure, the basic form of measurement is a simple temperature gauge. The construction of the gauges is quite varied, ranging from a bimetallic device to the filled systems. When transmis sion is involved, the sensor becomes quite simple, taking the form v)l a thermocouple or a resistance temperature detector (RTD). The monitor does the translation from the native signal to a temperature readout ()r signal proportional to temperature. 

Temperature. The simplest temperature sensor/ control systems typically use a bimetallic thermostat... 

Thermostats—bimetallic strip, snap-action disk, and thermostatic cable Continuous discrete conductors Thermistor sensors Rate of temperature rise Copper tubing heat-actuated devices (HADs) Thermoelectric Combined rate of rise/fixed temperature Rate compensation Oil mist ... 

Heukel, S. Silicon Microvalve Fabricated on Bimetallic Diaphragms, Sensors, 4 (December 1991). 

Different SPM systems were developed to study the thermal properties. Thus a tiny thermocouple can be used to measure the heat flow from the surface and to test the local thermo conductivity of polymer surfaces [161]. Recently, a bimetallic cantilever has been used as temperature sensor to investigate phase transitions of n-alkanes with a heat sensitivity of 500 pj for a sample mass as low as to... 

There are two types of thermal sensors the rate-of-rise sensor and the absolute temperature sensor. Fixed temperature sensors are usually either bimetallic or low-melting-point fusible link devices that activate sprinklers or other extinguishing devices. 

The d-f heteronuclear or lanthanide-transition metal (abbreviated as Ln-M) complexes attract interest from both academic and industry because of the challenge for their synthesis, the novelty of their structures, and their potential application as advanced materials, such as molecular or nano magnets,bimetallic catalysts, and sensors. The complexes can be assigned to three categories based on the nature of the Ln-M interaction (a) complexes with direct Ln-M bonding, (b) complexes with Ln-M interactions bridged by ligands, and (c) the complexes with ionically associated Ln-coordination units and M-coordination units. Most of the d-f heteronuclear complexes of carboxylic acids reported so far are found with type (b) structure, and very few of them are of structure type (c). The lanthanides and the transition metals in these complexes are far away from each other, and no direct Ln-M interactions have been observed. 

Bimetallic Pt-Sn catalysts are useful commercially, e.g., for hydrocarbon conversion reactions. In many catalysts, Pt-Sn alloys are formed and play an important role in the catalysis. This is particularly true in recent reports of highly selective oxidative dehydrogenation of alkanes [37]. In addition, Pt-Sn alloys have been investigated as electrocatalysts for fuel cells and may have applications as gas sensors. Characterization of the composition and geometric structure of single-crystal Pt-Sn alloy surfaces is important for developing improved correlations of structure with activity and/or selectivity of Pt-Sn catalysts and electrocatalysts. 

Dutta, A., Ishihara, T. and Nishiguchi, H. (2004) An amperometric solid-state gas sensor using a LaGaOj-based perovskite oxide electrolyte for detecting hydrocarbon in exhaust gas. A bimetallic anode for improving sensitivity at low temperatures. Chem. Mater., 16 (24), 5198-204. 

Xiao F, Zhao FQ, Zeng BZ et al (2009) Nonenzymatic glucose sensor based on ultrasonic-electrodeposition of bimetallic PtM (M=Ru, Pd and Au) nanoparticles on carbon nanotubes-ionic liquid composite film. Biosens Bioelectron 24 3481-3486... 

Bimetallic thermometers measure temperature by the change in physical dimension of the sensor. They have often been used [80]. The sensor consists of a composite strip of material, normally in a helical shape, formed by two different metals Differences in the thermal expansion of the two metals cause the curvature of the strip to be a function of temperature. The strip is used as a temperature indicator with a self-contained scale. Bimetallic thermometers have been used at temperatures from -185 to 425°C. The precision and accuracy of such thermometers are described in Ref. 81. 

Nakabeppu et al. [58] describe the use of composite cantilevers made from tin or gold deposited on conventional silicon nitride AFM probes to detect spatial variations in temperature across an indium/tin oxide heater. Differential thermal expansion of the bimetallic elements causes the beam to bend. This movement is monitored using the AFM optical lever deflection detection system. In order to separate thermal deflection of the beam from displacement of the cantilever caused by the sample topography, an intermittent contact mode of operation is employed. Measurements were made under vacuum so as to minimize heat loss. A more practical use of this technology is in the form of miniature chemical and thermal sensors [59]. This approach has been used to perform thermal analysis on picolitre volumes of materisd deposited on the end of a bimetallic cantilever [60]. Arrays of such devices have applications as highly sensitive electronic noses . 

Inorganic nanoshell-coated organic polystyrene beads with well-defined nanostructures are attractive because of their applications in the fields of SERS, catalysis, biochemistry, and chemical sensors. The core-shell type composite materials are in the frontier of advanced research, in which the shell component determines the surface properties and the core component indirectly induces the other properties of the system. Bimetallic nanosheUs on functionalized polystyrene beads have been fabricated through a layer-by-layer deposition pathway involving the electrostatic interaction of the polystyrene moiety. 

The American company IC-Sensors offers a thermomechanically driven microvalve (with 2/2-way functionality) for gases (Fig. 6.113) [315]. The valve consists of an elastically suspended valve reed and a rigid valve base with a valve opening. The valve reed can be put into motion using the thermomechanical (bimetallic) effect. The temperature of the bimetallic structure of aluminium and silicon is used to control the actuator force. The normally closed valves are designed for a maximum pressure of 10... 200kPa. Gas flows of up to 0.11/min are achieved with a driving power of 300 mW. 

Zynio SA, Samoylov AV, Surovtseva ER, Mirsky VM, Shirshov YM (2002) Bimetallic layers increase sensitivity of affinity sensors based on surface plasmon resonance. Sensors 2(2) 62-70... 

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