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Instrumentation pneumatic systems

Instrument Society of America 400 Stanwix Street Pittsburgh, Pa. 15222 Standards l ibrary for Measurement and Control, 12th ed., 1994. Instmmentation standards and recommended practices abstracted from those of 19 societies, the U.S. Government, the Canadian Standards Association, and the British Standards Institute. Covers control instmments, including rotameters, aimunciators, transducers, thermocouples, flow meters, and pneumatic systems (see... [Pg.23]

The degree of drying desired will vary with the pneumatic equipment and application involved. The aim is to eliminate further condensation in the airlines and pneumatic tools or devices. Prevailing atmospheric conditions also have an influence on the approach that is most effective. In many 100-psig installations, a dew point at line pressure of from 500°F to 350°F is adequate. Other applications, such as instrument air systems, will require dew points of minus 500°F. [Pg.640]

Some proportional detectors are combined in the same instrument with a suitable transducer which can perform some of the functions of a controller. For example, for pneumatic systems the primary sensing element actuates a variable air jet, thus modulating an air pressure which is transmitted to a further controller or direct to the controlled device. Electric and electronic detectors such as the infrared detector include the sensing and amplifying circuits of the instrument. [Pg.327]

The basic components of the solid state spectrometer are the same as the solution-phase instrument data system, pulse programmer, observe and decoupler transmitters, magnetic system, and probes. In addition, high-power amplifiers are required for the two transmitters and a pneumatic spinning unit to achieve the necessary spin rates for MAS. Normally, the observe transmitter for 13C work requires broadband amplification of approximately 400 W of power for a 5.87-T, 250-MHz instrument. The amplifier should have triggering capabilities so that only the radiofrequency (rf) pulse is amplified. This will minimize noise contributions to the measured spectrum. So that the Hartmann-Hahn condition may be achieved, the decoupler amplifier must produce an rf signal at one-fourth the power level of the observe channel for carbon work. [Pg.107]

Clearing any system with instrument air as a pressure source is a bad idea. Other pneumatic sources, such as utility air, plant air, or nitrogen, should be used instead. However, the Three Mile Island instrument air was at a lower pressure than the water stream on the resin polisher system. Despite the presence of check valves, there was a reverse flow water entered the instrument air system causing several instruments to fail, and the turbine tripped. Through a series of other errors, the water covering of the radioactive core was uncovered, allowing an escape of a small amount of radioactivity. Due to the widespread negative public reaction, the U.S. nuclear industry received a setback. If it were not for that improper hose connection or the erroneous one-minute modification,... [Pg.134]

Booster relays are designed to provide extra flow capacity for the instrument air system, which decreases the dynamic response time of the control valve (i.e., the time for most of a change to occur). Booster relays are used on valve actuators for large valves that require a large volume of instrument air to move the valve stem. Booster relays use the pneumatic signal as input and adjust the pressure of a high flow rate capacity instrument air system that provides pressure directly to the diaphragm of the valve actuator. [Pg.1191]

Figure 8.14. Schematic diagram of a pneumatic system retrofitted to a capillary electrophoresis instrument for capillary electrochromatography with simultaneous pressurization of the column inlet and outlet reservoirs. Figure 8.14. Schematic diagram of a pneumatic system retrofitted to a capillary electrophoresis instrument for capillary electrochromatography with simultaneous pressurization of the column inlet and outlet reservoirs.
The pneumatic system comprises of various parts. The air or any other gas is pressed by the compressor through the pneumatic volume, capillary and pneumatic volume, which smoothen the flow and pressure at the measuring system inlet. The air flow is determined from the pressure difference along the flow capillary via a differential pressure sensor. The control of the volume of separating bubbles is arranged by a deflector located opposite to the capillary at a definite distance (Miller et al. 1994). The optimum internal gas volume of the instrument and selection of the right capillary are two important points in the design of the device as discussed below. [Pg.82]

Fig. 28.8. The CT- and MR-compatible pneumatic robotic instrument guiding system (Innomotion) provides 6-DOF guidance and optional remote biopsy needle insertion... Fig. 28.8. The CT- and MR-compatible pneumatic robotic instrument guiding system (Innomotion) provides 6-DOF guidance and optional remote biopsy needle insertion...
Medical Devices. Pneumatics is being used more in medical devices. When the dentist, drill or pohsher in hand, steps on a small plate, a pneumatic system is activated that drives the instrument in a circular motion at a very high speed. Pneumatic systems are excellent for applications in patient ventilators. Ventilators can either take over breathing for an extremely sick patient or assist a patient with some breathing ability. [Pg.1504]

Hot water layer system instrumentation Reactor water treatment system instrumentation Demineralized water system instrumentation Active effluents system instrumentation Supervised area ventilation system instrumentation Reactor hall ventilation system instrumentation Non restricted area ventilation system instrumentation Ventilation system water supply instrumentation Pneumatic transport system instrumentation... [Pg.50]

The case study described here concerns a human factors audit of a computer controlled process system which was being introduced in a distillation imit of a chemical plant. The unit was in transition from replacing its pneumatic panel instrumentation with the new system. However, control had not yet been transferred and the staff were still using the panel instrumentation. The role of the project was to evaluate a preliminary design of the computer-based display system and provide recommendations for future development. [Pg.330]

A central component of the LC instrument is the pump, for its characteristics can strongly influence an analysis (e.g., flow reproducibility). The three principal types of systems— pneumatic, syringe type and reciprocating piston—have been reviewed in the literature (18-20). [Pg.232]

In the pneumatic pumping system, the pressure (and not the flow rate) is maintained constant as variations in chromatographic conditions occur. Thus, a change in mobile phase viscosity (e.g. gradient elution) or column back pressure will result in a change in flow rate for these types of pumps. The gas displacement pump in which a solvent is delivered to the column by gas pressure is an example of such a pneumatic pump. The gas displacement system is among the least expensive pumps available and is found in several low cost instruments. While the pump is nonpulsating and hence, produces low noise levels with the detectors in current use, its flow stability and reproducibility are only adequate. In addition, its upper pressure limit is only 2000 psi which may be too low in certain applications. [Pg.232]

In Figure 8.12, the basic set-up of an ICP-MS instrument is presented as a block diagram, consisting of a sample introduction system, the inductively coupled argon plasma (ICP) and the mass-specific detector. By far the most commonly applied sample introduction technique is a pneumatic nebuliser, in which a stream of argon (typically 1 I.min ), expanding with high... [Pg.652]

Basic Process Control System (BPCS) - Pneumatic, electronic, hydraulic or programmable instruments and mechanisms that monitor and/or operate a facility or system to achieve a desired function, i.e., flow control, temperature measurement, etc., which are supervised by human observation. [Pg.283]

A modern gas chromatograph, whether configured for packed or capillary column use, consists of several basic components. All of them must be properly chosen and operated for successful analysis. These are pneumatics and gas-handling systems, an injection device, an inlet, a column oven and column, a detector and a data system. Since the inception of GC in the 1950s, instrumentation has evolved significantly as new techniques and technologies were developed. This section provides an overview of the major components of a modern gas chromatograph, with details about how to choose components based on analytical needs, and applications. [Pg.458]

An even greater pitfall into which many young process control engineers fall, particularly in recent years, is to get so involved in the fancy computer control hardware that is now available that they lose sight of the process control objectives. All the beautifiil CRT displays and the blue smoke and mirrors that computer control salespersons are notorious for using to sell hardware and software can easily seduce the unsuspecting control engineer. Keep in mind your main objective to come up with an effective control system. How you implement it, in a sophisticated computer or in simple pneumatic instruments, is of much less importance. [Pg.8]

In addition to concentric pneumatic nebulizers that are used most frequently for the majority of atomic spectrometric systems, a range of other nebulizers also exist. Some nebulizers that are used for plasma instrumentation, e.g. direct injection nebulizers (DIN) or ultrasonic nebulizers (USN), increase... [Pg.155]


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See also in sourсe #XX -- [ Pg.341 ]




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