Recording pyrometers

Roberts-Austin (Sir) William Chandler (1843-1902) Brit, metal., designed automatic recording pyrometer with Pt-thermocouples for high-temperature study, demonstrated that that diffusion can occur between attached sheets of gold and led Rodovsky Bavor jun. from Bavorov (or Hustifan) (1526-1592), Czech alchemists, author of possibly the first book on cookery... 

Figure 8-1 indicates the location of the various control instruments that may be used in a topping plant. Among the most important are (1) top temperature controller (2) recording pyrometer at vaporizer and at inlet and outlet of pipestill (3) pressure at inlet and outlet of pipestill, at charge pump, and in tower (4) rate of flow of crude oil and (5) level controls at bottom of tower and the side-draw plates. Control instruments are extensively used in natural gasoline plants (Fig. 8-2). Finally, Figs. 12-6 and 12-7 on dewaxing, and Fig. 20-11 on alkylation, show instrumentation.

Most forms of carbon interact strongly with microwaves. When irradiated at 2.45 GHz, amorphous carbon and graphite in powdered form rapidly reach ca. 1000 °C within 1 min of irradiation. An example of a solvent-free Diels-Alder reaction performed on a graphite support is shown in Scheme 4.5. Here, diethyl fuma-rate and anthracene adsorbed on graphite reacted within 1 min of microwave irradiation under open-vessel conditions to provide the corresponding cycloadduct in 92% yield [14]. The maximum temperature recorded by an IR-pyrometer was 370 °C. In other cases, it was necessary to reduce the microwave power and therefore the reaction temperature in order to avoid retro-Diels-Alder reactions [13]. 

Record of the heat treatment temperature cycle shall be monitored by attached thermocouple pyrometers or other suitable methods to ensure that the requirements are met. See para. GR-3.4.12 for attachment of thermocouples by the capacitor discharge method of welding. 

The metals were either packed in high-purity graphite and heated in an Ar atmosphere or heated in a pure-nitrogen atmosphere up to 2500 K in a cold-wall autoclave. The temperature was recorded by thermocouples or two-color IR pyrometers. Gas pressures (mbar range up to 40 bar) were measured with piezoelectric gauges. The conditions were recorded on a PC equipped with an A/D converter. Extended heating periods could be maintained without any change in experimental conditions. 

A temperature of 1750 F. (or 2000 F.) is reached in 1 minute on the coating surface and maintained for 0.5 hour. The pyrometers indicate the temperature differential (insulative ability of the fire-retardant coating) between the name temperature and the bare metal temperature. Results should be recorded on a graph indicating time vs. temperature and evaluated on a relative basis. 

Furnace Simulation. The purpose of this example is to demonstrate the capability of the PF60 system to predict yield structure and the tubeskin temperature in commercial operating furnaces. Table II summarizes the data from a commercial reactor processing primarily propane as feedstock. At the time the data were taken, the furnace had been on stream less than four days and hence an unfouled radiant coil condition could be assumed. The yields were recorded by on-line chromatographs. The tubeskin temperatures were measured in 15 locations by calibrated infrared pyrometers. 

Recording Pyrometry.—The pyrometers which can be made to record automatically fall under the following classifications (1) Gas, saturated vapor, and liquid thermometers (2) resistance thermometers (3) thermoelectric pyrometers (4) radiation pyrometers. 

Manual Signaling.—This is of greatest use in extensive pyrometer installations having a central pyrometer station for indicators and recorders. Signals... 

The choice of a temperature detection device depends on the maximum temperature desired, the chemical reactivity of the sample, and the sensitivity of the dc amplifier and the recording equipment. The most common means of differential temperature detection is with thermocouples, although thermopiles, thermistors, and resistance elements have been employed. For high-temperature studies, an optical pyrometer may also be practical. 

Thermal, microstructure, and x-ray phase methods of analysis were employed. Thermal analysis was conducted with a Kurnakov pyrometer and an NTR-62 temperature recorder. The alloys studied thermographically were crushed and placed in Stepanov quartz vessels in amounts of 1.8 g. Then, the vessels were evacuated and sealed. Platinum-platinum/rhodium thermocouples were employed in the thermographic studies. 

The epoxy prepolymer and the curing agent were mixed together prior to use, then the epoxy mixture (13 g) was poured into moulds (inside dimension 96 mmx 16 mmx8 mm), which were irradiated in a microwave applicator with TEqi propagation mode. The sample temperature was measured continuously by means of an infrared pyrometer that gave the surface temperature and fiber-optic thermometer that recorded the bulk temperature. Samples cured by both thermal... 

The development of thermocouple, as an accurate temperature measuring device, was rapidly followed by Osmond (1886) who investigated the heating and cooling behavior of iron and steel with a view to elucidating the effects of carbon so that he introduced thermal analysis to then most important field of metallurgy. Roberts-Austen (1891), however, is known to construct a device to give a continuous record of the output from thermocouple ands he termed it as Thermoelectric Pyrometer , see Fig. 77. 

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