Temperature measurement electronic methods

Measuring body temperature is important for the detection of disease and assessment of the response to treatments. The first thermometer was developed by Galileo in 1603. Thermometers for measuring body temperature have been in use since about 1870. The first measurements taken were axillary, and later oral and rectal measuring methods were introduced. The working principle of those thermometers, the expansion of matter by temperature increase, is still used for body temperature measurement in mercury-in-glass thermometers. Electronic thermo-... 

The field electron microscope permits determination of the distribution of emission and thereby of the covering of the monocrystal with foreign molecules at room temperature. By a method analogous to that shown in Fig, 5, the work function can be measured too. In the anode, covered by a luminous substance, a small opening is made in front of a collector (Fig. 7). By a lateral magnetic field or by adjustment of the cathode, a certain point of the monocrystal is focused on the opening. 

There is another approach which can be used in suitable circumstances. Developed by Kowalik and Kruger (31), it involves measuring the population of an excited atomic state by LIFS. If the ground state population is known to be uniform in the flow field, then information about temperature can be inferred. They have used the method to measure electron number density in MHD plasma flows. 

Chapters XVI-XX deal with basic experimental methods of broad value in many types of experimental work—electronic measurements, temperature measurement and control, vacuum techniques, diverse instruments that are widely used, and miscellaneous laboratory procedures. These chapters have been revised and updated in various ways. In the case of Chapters XVI and XVIII, the text has also been shortened from that which appeared in the seventh edition. Finally, Chapter XXI presents a thorough discussion of least-squares fitting procedures. 

This method has been criticized because the probe, in drawing current, disturbs the normal electron and ion distributions. In one alternative solution that has been suggested, a floating double probe is used (J2). Just how important this disturbance is, still seems to be a matter of some discussion. Other methods, such as microwave attenuation, have been tried for measuring electron temperatures, but little has been published about the techniques. 

Residual moisture is the low level of water, usually in the range of less than 1-3% (wt/wt), remaining in a freeze-dried product after the freeze-drying (vacuum sublimation) process [1-5] is complete. Nail [6] has described in-process methods to monitor the endpoint of freeze-drying using residual gas analysis, pressure rise, comparative pressure measurement, and product temperature measurement. Roy and Pikal [7] used an electronic moisture sensor inside the lyophilization chamber. Residual moisture [8] content is important in the final freeze-dried product because it affects the potency of the product, its long-term stability, and the official shelf life of the product. 

In the equilibrium methods the electron is treated the same as any other chemical reactant. The measurement of the electron affinity of a molecule involves the measurement of the equilibrium constant for the reaction of thermal electrons with a molecule (AB + e(—) = AB(—)) at some specific temperature or series of temperatures. The equilibrium technique requires (1) a source of thermal electrons, (2) a source of the test species, (3) a method of measuring the equilibrium concentrations of the neutral species, negative ions, and free thermal electrons, and (4) a temperature measurement. The equilibrium constant is directly related to the Ea by this equation ... 

The electron temperature (Tg), electron density (ng) and electron energy distribution function for a plasma sustained in an argon/benzene mixture were measured by double and triple plasma-probe methods. Each probe was heated up to 1000 K with a sheathed heater, which was inserted into the probe, in order to prevent... 

Temperature measurements are used to characterize wastewater, as well as to make corrections for other tests that are temperature sensitive. Temperature is measured by allowing a thermometer or electronic device to come to thermal equilibrium with the water, by Standard Method 2550 (Standard Methods, 1998). Thermometers should be mercury in glass types, marked to a precision of 0.1 °C. These should be well calibrated against primary standard thermometers, or against the... 

Various techniques are used to obtain information on the active centers of catalysts, such as selective poisoning, measurement of the catalyst acidity and its strength, field electron and ion microscopy, infrared spectroscopy, fiash-filament desorption, differential isotopic method, etc. A temperature-programmed desorption method, which will be described and discussed in the present article, is in principle similar to the fiash-filament desorption method, reviewed recently by Ehrlich (1). It differs, however, from it in several respects. Modifications have been necessary in order to make the construction and operation of the apparatus easier and to adapt it to studies of materials other than metals, for example the conventional oxide catalysts. The conditions employed are much more similar to those ordinarily used in catalytic reactions than is the case with the fiash-filament method. An additional important feature of the modified technique is that it permits in some cases simultaneous study of a chemisorption process and the surface reaction which accompanies it. At the same time the modifications made have sacrificed some of the simplicity of the flash-filament method. For example, an obvious complication may arise from the porous structure of the conventional catalytic materials, in contrast to the relatively smooth surfaces of metal filaments. The potential presence of this and other complications requires extension of the relatively simple theoretical treatment of flash-filament desorption to more complicated cases. 

The characteristic parameters generally considered are the temperature and electron density which are of primary importance under equilibrium coiulitions For example, with a D.C. plasma generator, two different zones have been pointed out in a nitrogen plasma jet at atmospheric pressure The first zone is such that 10 < n < lO cm and 9000 K < T < 15000 K, and the different criteria show that LTE is achieved. The second zone has a low electronic density 10 < n, < < 10 cm , a quite low temperature 3000 K < T < 7000 K, and uilibrium is not realized, due in part to diffusion. Nevertheless in both cases, the relaxation times of rotation-rotation, and rotation-translation exchanges are sufficiently low to consider the rotational and the translational temperatures to be equal, b) Spectroscopic measurement methods... 

The following tables summarize the results of experimental work function data. Tjub is the substrate temperature in K during deposition. RT denotes room temperature. The methods of work function measurement are VC Vibrating capacitor method RP Retarding potential method SEC(E) and SEC(P) Electron- and photon-induced secondary electron method respectively FE Field emission method. A( )min is the work function change at the minimum, A( )ML is the work function change at one saturated monolayer, fig is the initial dipole moment. Where appears in the table, a minimum was not observed. The tables are adapted and updated from [89A1],... 

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