Temperature RTDs

Surface Modification. A polydiene film (supported on a microscope slide) was immersed in a stirred, room temperature, RTD-acetonitrile solution of known concentration contained in a large glass-stoppered test tube. After a specific reaction time, the film was removed from the solution, washed with acetonitrile, water, and acetonitrile again, and dried under vacuum (Step 1). Films subsequently treated with base were immersed in aqueous solutions for 5-15 min. They were then washed with water and CH3CN, and vacuum dried (Step 2). Some films were aged in air at room temperature. 

Compound 48 is a more sophisticated device with two barriers that resembles a linear quantum dot or a RTD. 46 was synthesized from terephthaldehyde and l-iodo-4-lithiobenzene (Scheme 3.28). Reduction of the two hydroxyl moieties on 46 afforded 47 that was further coupled with two equivalents of alligator clip 9 to afford the desired 48. This compound did indeed respond as a room temperature RTD when placed in the nanopore configuration. ... 

TABLE 8-7 Recommended Temperature Measurement Ranges for RTDs and Thermocouples... 

For most points requiring temperature monitoring, either thermocouples or resistive thermal detectors (RTD s) can be used. Each type of temperature transducer has its own advantages and disadvantages, and both should be considered when temperature is to be measured. Since there is considerable confusion in this area, a short discussion of the two types of transducers is necessaiy. 

Since the higher thermal conduc tivity material (copper or bronze) is a much better bearing material than the conventional steel backing, it is possible to reduce the babbitt thickness to. 010-030 inch. Embedded thermocouples and RTDs will signal distress in the bearing if properly positioned. Temperature-monitoring systems have been found to be more accurate than axial-position indicators, which tend to have linearity problems at high temperatures. 

A factor in addition to the RTD and temperature distribution that affects the molecular weight distribution (MWD) is the nature of the chemical reaciion. If the period during which the molecule is growing is short compared with the residence time in the reactor, the MWD in a batch reactor is broader than in a CSTR. This situation holds for many free radical and ionic polymerization processes where the reaction intermediates are very short hved. In cases where the growth period is the same as the residence time in the reactor, the MWD is narrower in batch than in CSTR. Polymerizations that have no termination step—for instance, polycondensations—are of this type. This topic is treated by Denbigh (J. Applied Chem., 1, 227 [1951]). 

Temperature detectors embedded in the motor winding give close, accurate indication of motor temperature. Both conventional resistance temperature detec tors (RTD) and special thermistors (highly temperature-sensitive nonlinear resistors) are used. With appropriate auxiliaries these devices can indicate or record motor temperature, alarm, and/or shut down the motor. 

Monitor temperature of material being dried by infrared, resistance temperature device, (RTD) etc. 

HT motors must have a minimum six numbers of resistance temperature detectors (RTDs) (See section 12.8). 

Embedded temperature detectors are resistance temperature detectors (RTDs) or resistance thermometers or thermocouples, built within the machine during manufacture at points that are not accessible when the machine has been assembled. This method is generally employed for the likely hot spots of a machine such as the slot portion and the overhangs of the stator windings. 

Motor winding temperature detection (by PTC thermistors and RTDs) 12/306... 

This is a later introduction in the sensing of temperature compared to the more conventional types of temperature devices available in an embedded temperature detector (ETD), such as a thermocouple or a resistance temperature detector (RTD) described below. Thermistors can be one of the following types ... 

The exact resistance variations of a F, - 100, RTD over a range of temperatures are given in Table 12.2, and not very different from those calculated by the above equation and drawn in Figure 12.41. 

RTDs or thermocouples These are normally embedded in the stator windings as illustrated in Figures 12.42 and 12.39(a). The winding temperature can now be monitored continually and a temperature replica of the machine obtained at any time. Figure 12.39(b) shows... 

Locate the RTDs at the likely hot spots, as at the joints of the busbars. Figure 14.2 illustrates the likely locations of the RTDs. The test may be carried out as noted earlier and temperature readings tabulated at 30-minute or l-hour intervals, whichever is more appropriate. The temperature rise, estimated with the highest temperature recorded by any of the RTDs, would refer to the ambient... 

If = temperature rise estimated at the test location 6 = ambient temperature at the test location 0i, = highest temperature recorded by any of the RTDs... 

The eleetrieal system should be eheeked to ensure that the Resis-tanee Temperature Deteetors (RTDs) are indieating the proper temperature. This temperature should have the same reading as the oil drain thermometer (usually a dial indieator). 

Total temperature is the temperature rise in the gas if its veloeity is brought to rest in a reversible adiabatie manner. Total temperature ean be measured by the insertion of a thermocouple, RTD or thermometer in the fluid stream. The relationship between the total temperature and static temperature can be given ... 

Temperature sensors, sueh as RTDs (Resistanee Temperature Deteetors), thermoeouples, and thermistors, ean be installed direetly in the thrust bearing to measure metal temperature. The installation shown in Figure 21-9 has the RTD embedded in the babbitted surfaee. It is in the most sensitive... 

Verifying temperature is the second most important aspect of any compressor operation. As with pressure, the basic form of measurement is a simple temperature gauge. The construction of the gauges is quite varied, ranging from a bimetallic device to the filled systems. When transmis sion is involved, the sensor becomes quite simple, taking the form v)l a thermocouple or a resistance temperature detector (RTD). The monitor does the translation from the native signal to a temperature readout ()r signal proportional to temperature. 

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