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Thermocouple, temperatures

Tungsten disilicide [12039-88-2] WSi2, forms bluish-gray tetragonal crystals (a = 0.3212 nm, c = 0.7880 nm). It is insoluble in water and melts at 2160°C. The compound is attacked by fluorine, chlorine, fused alkaUes, and HNO —HF. It may be used for high temperature thermocouples in combination with MOSi in an oxidising atmosphere. [Pg.291]

A high temperature thermocouple uses sihcon carbide (146). It is also used in lightning arrestors to protect high tension power lines, and in high loss factor microwave attenuators (147). [Pg.468]

Turbine inlet temperature. Thermocouple is constructed of platinum-platinum rhodium with the junction enclosed with ceramic insulation. Typically, 9-12 units are required at this stage. [Pg.668]

Instruments based on the contact principle can further be divided into two classes mechanical thermometers and electrical thermometers. Mechanical thermometers are based on the thermal expansion of a gas, a liquid, or a solid material. They are simple, robust, and do not normally require power to operate. Electrical resistance thermometers utilize the connection between the electrical resistance and the sensor temperature. Thermocouples are based on the phenomenon, where a temperature-dependent voltage is created in a circuit of two different metals. Semiconductor thermometers have a diode or transistor probe, or a more advanced integrated circuit, where the voltage of the semiconductor junctions is temperature dependent. All electrical meters are easy to incorporate with modern data acquisition systems. A summary of contact thermometer properties is shown in Table 12.3. [Pg.1136]

Trend the reactor temperature, cat-to-oil ratio, and atomizing steam rate. Verify the accuracy of the reactor temperature thermocouple and atomizing steam flow meter. [Pg.267]

The ITS-90 scale is designed to give temperatures T90 that do not differ from the Kelvin Thermodynamic Scale by more than the uncertainties associated with the measurement of the fixed points on the date of adoption of ITS-90 (January 1, 1990), to extend the low-temperature range previously covered by EPT-76, and to replace the high-temperature thermocouple measurements of IPTS-68 with platinum resistance thermometry. The result is a scale that has better agreement with thermodynamic temperatures, and much better continuity, reproducibility, and accuracy than all previous international scales. [Pg.618]

High-grade abrasive and lapping powder. High-temperature thermocouple. [Pg.236]

Electrical strip heaters, wrapped around the three stainless steel vessels enable them to be operated at any desired temperature. Thermocouples strapped to the surfaces of the vessels permit measurement, of their temperatures and, coupled to controllers, maintain the vessels at constant temperature or ensure that the rate of change of the temperature of the vessels is not excessive, so avoiding unnecessary thermal stress in them. [Pg.521]

At relatively high temperatures thermocouple thermometers are most commonly used to measure temperature. The thermoelectric power of three frequently used thermocouples is compared in Figure 10.2. The choice of thermocouple depends on the temperature range, the chemistry of the problem in question, sensitivity requirements and resistance towards thermal cycling. The temperature range and typical uncertainty of some of the most commonly used thermocouple thermometers are given in Table 10.2. [Pg.305]

Temperature thermocouples (Type-K 1 mm) at ten vertical positions in the bed (Figure 10). [Pg.76]

The construction of DTA apparatus is simple and consists of a furnace, differential thermocouple, temperature thermocouple, specimen holders, temperature programmer and recorder. The schematic of a typical DTA apparatus is shown in Figure 3.5. [Pg.183]

Some other applications of technetium are the following [283] use of some of its alloys as superconductors with high critical temperature, use of 99Tc in high-temperature thermocouples, construction of basic anticorrosive covers for nuclear reactors, etc. [Pg.469]

Figure 3.10 Effect of choice of x-axis temperature. Top x-axis corresponding to reference temperature. Middle idealized case for 2-axis corresponding to sample temperature (immersed thermocouple junction). Bottom x-axis corresponding to sample temperature (thermocouple junction in contact with underside of sample crucible). Figure 3.10 Effect of choice of x-axis temperature. Top x-axis corresponding to reference temperature. Middle idealized case for 2-axis corresponding to sample temperature (immersed thermocouple junction). Bottom x-axis corresponding to sample temperature (thermocouple junction in contact with underside of sample crucible).
Under slower heating rates in heat-flux DSC, the deviation of sample temperature from the setpoint during a self-feeding reaction may be maintained adequately small so as to be neglected. If the furnace feedback control is set to act based on the temperature of the sample (that is the sample temperature thermocouple is the control thermocouple), then the control system may be able to allow the transforming sample to heat itself at a constant rate, and the heat input from the furnace will retreat as needed. [Pg.61]

The filament calibration curve can be obtained by comparison against previously calibrated pyrometers or from the output of high-temperature thermocouples in thermal contact with... [Pg.211]

High Temperature Thermocouples, Manual 48125, probe T-1105, Aero... [Pg.133]

Use Additive to tungsten- and molybdenum-based alloys, electronic filaments, electrical contact material, high-temperature thermocouples, igniters for flash bulbs, refractory metal components of missiles, catalyst, plating of metals by electrolysis and vapor-phase deposition. [Pg.1088]

Use Alloy with platinum for high temperature thermocouples, furnace windings, laboratory crucibles, spinnerettes in rayon industry electrical contacts, jewelry, catalyst, optical instrument mirrors, elec-trodeposited coatings for metals, vacuum-deposited glass coatings, headlight reflectors. [Pg.1089]

The temperature of the furnace is continuously varied by a temperature controller, and the outputs from the balance and from the sample temperature thermocouple are logged by a computer fitted with a 16-bit dynamic range data acquisition board. The signals are processed via a program derived using a combination of Virtual Basic and C++ and the derivative of the TGA curve is used to control the heating program via the temperature controller. [Pg.3014]

For calorimetry performed at medium and high temperatures, thermocouples are used most frequently. For example, they are made of iron and constantan for medium temperatures or of platinum, rhodium, and iridium for high temperatures. Very frequently, a number of thermocouples linked in series in order to obtain a voltage measurable with sufficient precision, are used. [Pg.235]

A Can be used in high-temperature thermocouples in combination with MoSi2 in... [Pg.143]

In addition to reaction chambers and delivery systems, a number of supervising and sensor systems are of utmost importance for control and safety reasons. Sensors in automated workstations include measurement of temperature (thermocouple, thermistor, semiconductor), pressure, liquid flow and gas or liquid level. To monitor the presence or absence of vessels or devices, systems like capacitance, inductivity, ultrasonic monitors, magnetic sensors or optical sensors (reflective, beam interruption, color) can be integrated in automated workstations. [Pg.547]

Precise measurement of the sample temperature is also important, and the control of the temperature. Thermocouples can be highly reproduc-... [Pg.118]

For applications in adverse environments such as measurement in high-temperature furnaces, combustion chambers, and nuclear reactor cores, a protection tube is normally used with the thermocouple. Detailed descriptions on the selection of protection tubes and typical industrial high-temperature thermocouple assemblies are given in Ref. 36. [Pg.1192]

Samples were heated on a Zeiss hot stage, modified by replacing the platinum sample temperature thermocouple by a more sensitive copper-constantan couple, located as close as possible beneath the sample cover slip. A second temperature program thermocouple was placed in contact with the ceramic heater frame of the hot stage. The stage was programmed at 2°C. per minute with a slope-proportional band controller. Temperature was controlled to 0.05°C. Ice reference junctions were used on both samples and program thermocouples. The output of the sample-ice junction thermocouple was recorded on the 0.5 mv. per inch z-axis of the Moseley x-y recorder. [Pg.10]

A thermocouple generates an electrical potential which is roughly proportional to the difference in temperature between the two junctions (Seebeck effect), and is well suited for differential temperature measurements (10). It may also be used for absolute and relative temperature measurements by keeping one junction, the reference junction, at constant temperature. Thermocouples normally used in DTA instruments are shown in Table 6.1. The temperature limits listed are for relatively accurate measurements with... [Pg.305]

Figure 9.26. Schematic diagram of depolarized light intensity apparatus (74). A. unitron MPS microscope B. analyzer sheet C. polarizer sheet D. movable abbe condenser E. tungsten lamp F. movable hot stage G. heater H. program thermocouple 1. sample temperature thermocouple J. sample well K. pin plug terminal attached to microscope stand L. shielded cable to Du Pont module M. photocell N, movable mirror O. ocular P. Du Pont 900 differential thermal analyzer module Q. programmer R. X-Y recorder. Figure 9.26. Schematic diagram of depolarized light intensity apparatus (74). A. unitron MPS microscope B. analyzer sheet C. polarizer sheet D. movable abbe condenser E. tungsten lamp F. movable hot stage G. heater H. program thermocouple 1. sample temperature thermocouple J. sample well K. pin plug terminal attached to microscope stand L. shielded cable to Du Pont module M. photocell N, movable mirror O. ocular P. Du Pont 900 differential thermal analyzer module Q. programmer R. X-Y recorder.
The temperature thermocouple or T thermocouple is ihe thermocouple system used to measure temperature its position with respect to the sample should always be stated. Should another thermosensing device be used, its name should replace thermocouple. ... [Pg.806]

Combustion chamber temperature (thermocouple K-type of R-type)... [Pg.403]


See other pages where Thermocouple, temperatures is mentioned: [Pg.467]    [Pg.268]    [Pg.402]    [Pg.157]    [Pg.246]    [Pg.1442]    [Pg.107]    [Pg.107]    [Pg.107]    [Pg.384]    [Pg.2971]    [Pg.441]    [Pg.1214]    [Pg.492]    [Pg.402]    [Pg.403]    [Pg.401]    [Pg.872]   
See also in sourсe #XX -- [ Pg.32 , Pg.64 ]




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