Parameter analysis

Analysis parameters should be established to monitor the key indices of the compressor s dynamics and failure modes. These indices should include bearings, gear mesh, rotor passing frequencies, and mnning speed. However, because of its sensitivity to process instability and the normal tendency to thmst, the most critical monitoring parameter is axial movement of the male and female rotors. 

This is especially true in applications that use microprocessor/computer-based systems. These systems require a database that specifies the monitoring parameters, measurement routes, analysis parameters, and a variety of other information. This input is needed to acquire, trend, store, and report what is referred to as conditioned vibration data. 

The steps in developing such a database are (1) collection of machine and process data and (2) database setup. Input requirements of the software are machine and process specifications, analysis parameters, data filters, alert/alarm limits, and a variety of other parameters used to automate the data-acquisition process. 

The key elements of database setup discussed in this section are analysis parameter sets, data filters (i.e., band-widths, averaging, and weighting), limits for alerts and alarms, and data-acquisition routes. 

The software used to manage the data incorporates what are referred to as analysis parameter sets (APSs). APSs define and specify machine dynamics, components, and failure modes to be monitored. 

Analysis type As discussed previously, data-collection analyzers incorporate analysis parameter sets that allow the user to control the data-gathering process. APSs provide the option of selecting either frequency analysis for fixed-speed machinery or orders analysis for variable-speed machinery. 

The next step in establishing the program s database is to set up the analysis parameters that will be used to routinely monitor plant equipment. Each of these parameters will be based on the specific machine-train requirements that we have just developed. 

Normally for non-mechanical equipment the analysis parameter set will consist of the calculated values derived from measuring the thermal profile or process parameters. Each classification of equipment or system will have its own unique analysis parameter set. 

Water analysis parameters such as pH, electric conductivity, oxidation-reduction potential and temperature were measured in the field. Ionic chromatography, turbidimetry and ICP-OES were used for anions and metals. 

Electrolysis of mobile phase constituents will cause a continuous detector response (background current) resulting in a chromatographic baseline level that differs from the electrical detector zero-response level. The difference, baseline- offset, is an important analysis parameter, because baseline fluctuations (noise, drift) due to fluctuations in electrolysis conditions (potential, mobile phase flow rate, temperature) are proportional to baseline offset. See Figure 2-5 for an example of the influence of flow pulsation at different baseline offset... 

Soft sensors Fault detection Data reconciliation Statistical analysis Parameter estimation... 

Table 1 also contains some peak measurement/analysis parameters that might be investigated in a robustness test (see Section III.C). ° However, except from the detection wavelength, these parameters are hardly ever evaluated in a robustness test, even though they can have a large influence on the electropherogram. 

Operational and environmental factors Peak measurement/analysis parameters... 

FIGURE 3 Two electropherograms from one run, recorded with different settings for peak measurement/analysis parameters. 

Thermal analysis, moisture uptake and dynamic mechanical analysis was also accomplished on cured specimens. Thermal analysis parameters used to study cured specimens are the same as those described earlier to test resins. The moisture uptake in cured specimens was monitored by immersing dogbone shaped specimens in 71 C distilled water until no further weight gain is observed. A dynamic mechanical scan of a torsion bar of cured resin was obtained using the Rheometrics spectrometer with a temperature scan rate of 2°C/minute in nitrogen at a frequency of 1.6Hz. The following sections describe the results obtained from tests run on the two different BCB resin systems. Unless otherwise noted all tests have been run as specified above. 

Especially in academic science, data analysis often starts as an exploratory creative process with evolving ideas of the data analysis flow and rapidly changing analysis parameters or conditions. Therefore, data analysis software has to be extremely flexible in order not to limit the exploration of data. Furthermore, it is important that the data analysis process is comprehensible and easily readable at all time points to ensure that scientists can share their approach with colleagues and to better prevent conceptual mistakes. A third requirement to data analysis software is the minimization of effort and time a scientist has to invest to implement various methods. 

Table 9.2 Texture profile analysis parameters of raw potatoes of different cultivars... 

As with the need to use more than one method for calculating overall water usage, when precise numbers do not exist, it is advisable, where possible and relevant, to use more than one chemical analysis parameter to calculate cycles of concentration. 

GC Analysis Parameters. The parameters used for GC analysis are summarized in Table n. 

Choice of the analysis parameters. We can now summarize the various constraints introduced so far on the length T of the analysis window, its cutoff frequency coh, and the analysis rate R ... 

If analytical measurements are susceptible to variations in the analysis parameters or sample preparation conditions, the method must be suitably controlled or a precautionary statement must be included in the written procedure that alerts the chemist to the susceptibility. The method s system suitability parameters should be defined in such a way that meeting all system suitability criteria would ensure that the method is currently being performed within the acceptance window provided by validation robustness testing. 

Copasi (http //www.copasi.org) offers stochastic and deterministic time course simulation (the latter with LSODA, a stiff solver), steady state analysis (including stability), metabolic control analysis, elementary mode analysis, mass conservation analysis, parameter scans, and sliders for interactive parameter changes. It is platform-independent and offers a user-friendly GUI. 

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