Temperature coated thermocouple

Unless otherwise noted, all temperatures refer to internal temperatures measured with Teflon-coated thermocouples. 

Unless othenvise noted, all temperatures refer to internal temperatures measured with Teflon-coated thermocouples. Pyridine was purchased from Aldrich Chemical Compeiny, Inc., and used without further purification. 

Method A An aromatic or unsalurated compound and S02FCI or CC13F were placed in a poly(chloro-trifluoroethylene) reactor fitted with a Teflon stirrer and a Teflon-coated thermocouple. The mixture was cooled to — 25 C. Then a solution of VF5 in an equal volume of the solvent was added pordonwise, with stirring, at such a rate that the temperature was maintained at less than — 20 C. When the addition was complete, the mixture was poured onto crushed ice, the organic layer was separated, washed with cold H20, and dried (MgS04 or CaCl2). and the solvent was removed by distillation. 

Figure 4, Comparison of temperatures measured by suction pyrometer and by coated thermocouple...

Temperature proflles in spray flames were similar to those previously measured in gaseous diffusion flames. Measurement of temperature by coated thermocouple was more accurate than measurements by suction pyrometer within the temperature range and particular conditions of the spray flames investigated. Changes in temperature within the flame could be explained in terms of convection, reaction, entrainment, and dilution. 

Pugin [37] monitored the formation of an organolithium compound (butyl lithium in THF) and compared it to thermal and erosion measurements. He found a linear correlation between the rate of reaction for this process and the temperature rise of a coated thermocouple. This is an interesting result, but the slope of the line will almost certainly depend on the surface condition of the lithium pieces, on their size, and on the location of the solid relative to the ultrasonic source. These parameters should be carefully controlled in order to get reproducible results using this dosimeter. 

Kilham and Dunham [50], and Milson and Chigier [51] used silica coatings to prevent catalyic hydrogen atom recombination on the platinum in the thermocouple [64]. Madson and Theby [52] showed that uncoated platinum alloy thermocouples significantly overpredicted temperature, compared to silica-coated thermocouples in an 02/Ar/CH4 flame. Pollock... 

Several methods are used for the determination of the "active" zones in a vessel. These include optical (light diffraction), chemical, electrical, or mechanical (metal foil perforation), the measurement of local temperature increase (silicone-coated thermocouple), microdiffusion sensor, microvibration thermal sensor, microphones, or sonoluminescence.45 The principle of the latter consists of the oxidative degradation of luminol to aminophthalate under the action of the hydroxyl radical produced by water sonolysis. Aminophthalate is produced in an... 

Specialized alloys are used for high temperature appHcations on turbine blades, furnace parts, thermocouples, etc. These coatings can be as simple as iron—silicon—chromium or as exotic as chromium—aluminum—hafnium (36,41,52). 

Chemically Functional. Refractory coatings are used for corrosion-resistant high temperature service in gas turbine and diesel engines, components such as cmcibles, thermocouple protection tubing, valve parts, etc. 

The dynamic response of most sensors is usually much faster than the dynamics of the process itself. Temperature sensors are a notable and sometimes troublesome exception. The time constant of a thermocouple and a heavy thermowell can be 30 seconds or more. If the thermowell is coated with polymer or other goo, the response time can be several minutes. This can significantly degrade control performance. 

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