Guidelines for Instruments

New evaporation systems are designed to be controlled and supervised from modern control centers that assure safe, efficient, operation. The basic design philosophy is that all control systems be designed to fail safe in the event of instrument air failure, power failure, combination of both, or other utility service failure. Further, the control equipment should be designed to prevent release of flammable or toxic materials, and should be designed to permit safe maintenance of Instrumentation. 

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UKOOA (1999). Guidelines for Instrument-Based Protective Systems, Issue No.2, Clause 4.4.3. 

The response is subject to some experimental variables, chief among which are the flow-rates of hydrogen, air and the carrier gas. The instrument manufacturer s instructions should be followed closely to optimise these, although there is usually some leeway, as it is not easy to give general guidelines for instruments of different makes. 

Title Guidelines for Instrument-based Protective Systems... 

Appendix B of ISA S84.01 has basic guidelines for instruments in safety applications. 

The Guidelines for Process Equipment Reliability Data with Data Tables covers a variety of components used in the chemical process industry, including electrical equipment, analyzers, instrumentation and controls, detectors, heat exchangers, piping systems, rotating equipment (pump, compressor, and fan), valves, and fire protection systems. 

In most situations analysts can achieve a rapid reasonable separation of compounds using an appropriate standard CE method with generic operating conditions [877]. This eliminates or reduces dramatically the need for method development. Major instrumental error sources in CE are detection, integration and injection. General guidelines for validation of CE methods are available and similar to those of HPLC [878]. Validated CE methods often perform the same as, or better than, the corresponding HPLC methods. 

References Guidelines for Safe and Reliable Instrumented Protective Systems, American Institute of Chemical Engineers, New York, 2007 ISA TR84.00.04, Guidelines for the Implementation of ANSI/ISA 84.00.01-2004 (IEC 61511), Instrumentation, Systems, and Automation Society, N.C., 2005 ANSI/ISA 84.00.01-2004, Functional Safety Safety Instrumented Systems for the Process Industry Sector, Instrumentation, Systems, and Automation Society, N.C., 2004 IEC 61511, Functional Safety Safety Instrumented Systems for the Process Industry Sector, International Electrotechnical Commission, Geneva, Switzerland, 2003. 

It is important that personnel understand how to achieve safe operation, but not at the exclusion of other important considerations, such as reliability, operability, and maintainability. The chemical industry has also found significant benefit to plant productivity and operability when SIS work processes are used to design and manage other instrumented protective systems (IPS), such as those mitigating potential economic and business losses. The CCPS book (2007) Guidelines for Safe and Reliable Instrumented Protective Systems discusses the activities and quality control measures necessary to achieve safe and reliable operation throughout the IPS lifecycle. 

Guidance can be found in the CCPS book (2007) Guidelines for Safe and Reliable Instrumented Protective Systems related to the development of the process requirements specification. 

They are used as above, but in general they lead to more straightforward interpretations. The correction for instrumental fractionation involves an isotope pair for which the measurements are in agreement with the terrestrial ratio, whether this choice results from the measurement itself or from model considerations. In cases where all the ratios are different from the terrestrial ratios, model considerations are used to interpret the data. In the most common cases, one isotope displays wider variations than the others and constitutes a guideline for modeling the origin of the anomalies. 

However, those who have worked with smaller diameter columns have often experienced lower performance and other difficulties. This is primarily due to extra-column effects the bandspreading in the injector, detector and tubing, or the gradient delay volume of the instrument. Troubleshooting guidelines for sorting out the causes of these difficulties are available in Reference f. With proper care, 2-mm columns can be run on a standard modern HPLC instrument with few difficulties. Smaller i.d. columns require special instrumentation. 

Brown developed guidelines for the preparation of order-of-magni-tude and study capital cost estimates based upon the Lang and Hand methods. Brown modified Lang and Hand methods for materials of construction, instrumentation, and location factors. He found that the modified Hand and Garrett module factor methods gave results within 3.5 percent. 

The Instrumental Criteria Sub-committee of the Analytical Methods Committee has been active for many years in producing Guidelines for the Evaluation of Analytical Instrumentation. Since 1984, they have produced reports on atomic absorption, ICP, X-ray spectrometers, GLC, HPLC, ICP-MS, molecular fluorescence, UV-Vis-NIR, IR and CE. These are excellent source documents to facilitate the equipment qualification process. A current listing of these publications is given in Section 10.2. 

Australian Code of GMP for Therapeutic Goods, Medicinal Products Appendix D, Guidelines for Laboratory Instrumentation , 1991. 

Data have been generated to show guidelines for expected savings as a function of the number of instruments, number of operators, or number of samples per day (see Tables 8.1 and 8.2). These are estimative guidelines. Appropriate figures for a particular laboratory can be generated only by someone familiar with individual laboratory operation, the personnel, and the existing hardware. 

Over the past 40 years fluorine nuclear magnetic resonance (19F-NMR) spectroscopy has become the most prominent instrumental method for structure elucidation of organofluorine compounds. Consequently the amount of spectral data published has grown almost exponentially Unfortunately NMR data for fluonnated compounds are not as well, or as easily, organized as proton data To facilitate retrieval of fluorine NMR information and comparison of data, acquisition parameters should be clearly defined Guidelines for publication of NMR data have been established by the International Union for Pure and Applied Chemistry (IUPAC) [7] The following niles for acquisition and reporting of NMR data should be strictly observed... 

Dow s Critical Instruments Program describes identification of critical instruments, and provides guidelines for their design, installation, testing, maintenance, and documentation. 

It is best to establish specific stabilization parameters and their performance criteria for each well based on such factors as the aquifer properties the well construction detail the nature of contaminants of concern the sampling technique and field instrument specifications. However, this may be achievable only for wells with historical data on a long-term monitoring program. As a general practice, we may use the guidelines for the stabilization parameter criteria presented in Table 3.4. 

Table 5.4 summarizes the acceptance criteria for instrument, calibration, and method blanks. No contaminants of concern should be present in method blanks above the laboratory PQL. Equally important is that instrument blanks show no memory effects. If these conditions are not met, a possibility for false positive sample results becomes real. For decision on sample data with contaminated method blanks the chemist may rely on the following rules of the Functional Guidelines ... 

The Guidelines for Hazard Evaluation Procedures, Second Edition [5] also offers 45 pages of sample questions in its Appendix B. These questions cover process, (i.e., flowsheets and layout), equipment (reactors, heat exchangers, piping, and instrumentation), Operations, Maintenance, Personnel Safety, and other broad areas. 

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