Simultaneous measurement of temperature

A rate of flow is commonly measured by differentia pressure across an orifice, but many other devices also are used on occasion. Simultaneous measurements of temperature and pressure allow the flow measurement to be known in mass units. Direct mass flow... 

Fig. 24. Experimental setup for simultaneous measurements of temperature and NO concentration fields in a research SI engine.

Boyack, K. W., and Hedman, R. O. "Dual-Stokes CARS System for Simultaneous Measurement of Temperature and Multiple Species in Turbulent Flames." 23rd Symposium (International) on Combustion, The Combustion Institute, Rittsburgh, RA, 1990. 

Some years ago D. Stuerga designed a microwave reactor, called the RAMO (reac-teur autoclave microonde), which is not a commercial device. The microwave applicator and the reactor are original. The resonant frequency of the cavity can be controlled by varying the position of a plunger. The effective cavity power can be increased by three orders of magnitude. The autoclave is made of polymeric materials, which are microwave transparent, chemically inert, and sufficiently strong to accommodate the pressures induced. The reactants are placed in a Teflon flask inserted within a polyetherimide flask. A fiber-optic thermometry system, a pressure transducer, and a manometer enable simultaneous measurement of temperature and pressure within the reactor. The system is controlled by pressure. The reactor is shown in Fig. 2.32. 

Use of multiassays with simultaneous measurement of temperature profile, chemical components, microbial contamination, etc. 

This method consists of the simultaneous measurement of temperature at two positions, and X2, usually as their difference. It is illustrated by the following examples. 

Liquid Crystai Technique for Measuring Temperature, Figure 6 Flow chart of simultaneous measuring of temperature and velocity... 

Chamarthy P, Wereley ST, Garimella SV (2006) Simultaneous measurement of temperature and velocity using pPIV Proc ASME Int Mech Eng Congress Exposition, IMECE2006-14079, Chicago... 

Chan C C, Jin W, Rad A B et al., Simultaneous measurement of temperature and strain an artificial neural network approach , IEEE Photon. Technol Lett., 1998, 10(6), 854-6. 

The flux Ja is typically measured by pan evaporation, lake evaporation, cooling pond heat transfer or an eddy correlation technique that relates turbulent diffusion of water vapor to mass flux. The concentration of water vapor at elevation z, Ca(z), is determined from simultaneous measurements of temperature and relative humidity and an application of Equations 9.56 and 9.57. At the water surface (z = 0), it is assumed that the air temperature is equal to water temperature and that relative humidity is 100%, so water temperature measurements and Equation 9.56 are sufficient to determine Ca(z = 0). If the analog of heat transfer is used, then... 

Vahdation of the measurements may require the simultaneous measurement of pressure and temperature. Typical sample locations do not have thermowells and pressure indicators. Consequently, modifications will be reqmred to facilitate validation. 

Electrical Conductivity This is often a convenient and accurate measurement of salinity or chlorinity. Here, too, there is considerable variation with temperature, so that simultaneous observation of temperature is essential. Figure 2.16 shows the relationship between conductivity and chlorinity at various temperatures. 

The experimental investigations of boiling instability in parallel micro-channels have been carried out by simultaneous measurements of temporal variations of pressure drop, fluid and heater temperatures. The channel-to-channel interactions may affect pressure drop between the inlet and the outlet manifold as well as associated temperature of the fluid in the outlet manifold and heater temperature. Figure 6.37 illustrates this phenomenon for pressure drop in the heat sink that contains 13 micro-channels of d = 220 pm at mass flux G = 93.3kg/m s and heat flux q = 200kW/m. The temporal behavior of the pressure drop in the whole boiling system is shown in Fig. 6.37a. The considerable oscillations were caused by the flow pattern alternation, that is, by the liquid/two-phase alternating flow in the micro-channels. The pressure drop FFT is presented in Fig. 6.37b. Under... 

In our laboratory, the sonication (20 kHz, 250 W, Air atm) of an aqueous solution of 0.1 M AgN03 for 10, 20 and 30 min produced turbidity as given in Table 9.1. Simultaneous measurement of rise in temperature and conductance was also recorded. The data of Table 9.1, however, are only qualitative and the author does not confirm to their quantitative figures. The same is true for similar tables in the subsequent sections of the chapter. 

Sonication of 0.05 M Hg2(N03)2 solution for 10,20 and 30 min and the simultaneous measurements of conductivity, temperature change and turbidity (Table 9.2) indicated a rise in the turbidity due to the formation of an insoluble precipitate. This could probably be due to the formation of Hg2(OH)2, as a consequence of hydrolysis, along with Hg free radical and Hg° particles which could be responsible for increase in the turbidity after sonication. The turbidity increased further with time. Mobility of NO3 ions was more or less restricted due to resonance in this ion, which helped, in the smooth and uniform distribution of charge density over NO3 ion surface. Hence the contribution of NOJ ion towards the electrical conductance was perhaps much too less than the conduction of cationic species with which it was associated in the molecular (compound) form. Since in case of Hg2(N03)2, Hg2(OH)2 species were being formed which also destroyed the cationic nature of Hg22+, therefore a decrease in the electrical conductance of solution could be predicted. The simultaneous passivity of its anionic part did not increase the conductivity due to rise in temperature as anticipated and could be seen through the Table 9.2. These observations could now be summarized in reaction steps as under ... 

So how does the IRMS get its stability Collector slits are several times the width of the ion beams. This gives a flat-topped peak shape (Fig 6) which makes the ion current intensive to drift. The main source of drift is temperature variation which both affects the electronic components used for mass selection and caused expansion and contraction of mechanical parts. Simultaneous measurement of ion beams using a double or triple collector is more precise than sequential measurement by mass scanning with a single detector. Finally, frequent comparison of sample gas under identical conditions also contributes to stability. Ion beam stability is more important than resolution for isotopic measurements. 

The third block in Fig. 2.1 shows the various possible sensing modes. The basic operation mode of a micromachined metal-oxide sensor is the measurement of the resistance or impedance [69] of the sensitive layer at constant temperature. A well-known problem of metal-oxide-based sensors is their lack of selectivity. Additional information on the interaction of analyte and sensitive layer may lead to better gas discrimination. Micromachined sensors exhibit a low thermal time constant, which can be used to advantage by applying temperature-modulation techniques. The gas/oxide interaction characteristics and dynamics are observable in the measured sensor resistance. Various temperature modulation methods have been explored. The first method relies on a train of rectangular temperature pulses at variable temperature step heights [70-72]. This method was further developed to find optimized modulation curves [73]. Sinusoidal temperature modulation also has been applied, and the data were evaluated by Fourier transformation [75]. Another idea included the simultaneous measurement of the resistive and calorimetric microhotplate response by additionally monitoring the change in the heater resistance upon gas exposure [74-76]. 

T. Takada. Temperature drop of semiconductor gas sensor when exposed to reducing gases - simultaneous measurement of changes in sensor temperature and in resistance . Sensors and Actuators B66 (2000), 1-3. 

Therefore a particular method was chosen (4). We worked on a statistical population of crystals in order to minimize the dispersion and on simultaneous measurement of all faces in order to compare their growth rate under the same conditions of supersaturation and temperature. Therefore classical (R,o ) isotherms were obtained. Experimentally we grew at the same time and in the same solution a single crystal and twin. Whereas growth rate measurements of the forms hOL are relatively simple (thanks to the fact that the b axis is a binary axis) (Figure lb), the kinetic measurements of the p 110 and p llO forms are more difficult. 

The equilibrium solubility of an Fe oxide can be approached from two directions -precipitation and dissolution. The first method involves precipitating the oxide from a supersaturated solution of ions with stepwise or continuous addition of base und using potentiometric measurements to monitor pH and calculate Fej- in equilibrium with the solid phase until no further systematic change is detected. Alternatively the oxide is allowed to dissolve in an undersaturated solution, with simultaneous measurement of pH and Fejuntil equilibrium is reached. It is essential that neither a phase transformation nor recrystallization (formation of larger crystals) occurs during the experiment this may happen with ferrihydrite which transforms (at room temperature) to a more condensed, less soluble phase. A discussion of the details of these methods is given by Feitknecht and Schindler (1963) and by Schindler (1963). 

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