Quality control check points

Check Lists. Tables I and II list groups of quality control check points which should be monitored for each wine lot during the corresponding phases in the winery. The quality control manager should... 

Table I. Quality Control Check Points—Phase I...

Forces more attention to quality of execution - the Gates become quality control check points for product launch/retire... 

Rich Manser and Frank Jones collected the field data used in this modeling exercise. Rich Manser also tested the modeling procedure during preliminary computer runs. Aldicarb analyses were performed by laboratories at the Univ. of Wise.-Stevens Point and the Univ. of Wise.-Madison. Quality control checks on spiked samples were performed by Union Carbide. Funds for the computer simulation were provided by a grant from the ARCO Foundation. 

Adequate in-process quality control is essential for producing consistent magnesia that meets industry requirements. There are numerous points along the process train, from incoming dolime quality to finished product, that require periodic quality control checks. 

The fourth means of avoiding contamination from personnel sources is by localized protection of critical operations that necessitate manual intervention. This includes point of All and other operations like connecting and disconnecting feed lines, loading rubber plugs into hoppers, taking samples for quality control checks, etc. The issue to address in connection with localized protection is the extent to which it should be applied. There are two methods (a) total containment in an isolator or glove-box, and (b) protection by means of laminar Aow Altered air. 

Bubble Point Test. This is a widely used test to establish the largest pore size available in the filter under test. It is also regarded as a standard integrity and quality control check... 

At this point in the manufacturing sequence, a series of characterization procedures are usually inserted to check the slip quality and uniformity. They are standard in-process quality control checks to make sure that the slip is the same as the batches that preceded it into manufacture. The characteristics monitored are ... 

Check the calibration of the transducer on a monthly basis or when needed as indicated from the quality control checks (see Section 11). The calibration of the transducer is checked using two reference points, zero pressure (<0.1 kPa) and the ambient barometric pressure. 

Major categories of process Raman applications include reaction monitoring, in-process quality checks, and mobile or field point measurements. Quality control laboratory applications often are converted to a continuous process monitoring approach, or could simply be viewed as part of a larger production process. 

Even in modern quality control laboratories you will find a number of traditional methods for the identification of single flavour compounds, for example the estimation of optical rotation, refractive index, density and melting point, since these methods are generally accepted, effective and less time-consuming. Especially for the purpose of fast identification checks of more complex systems, spectroscopic methods, above all infrared (IR) and near-IR spectroscopy, are gaining more and more importance. 

Solution viscosity is an excellent method for quality control for relatively uniform polymer samples. There is an ASTM test method for determining inherent viscosity (ASTM D 4603) that uses polyethylene terephthalate) and one for determining intrinsic viscosity of cellulose (ASTM D 1795) that describes a one-point method for estimating intrinsic viscosity. The result is useful as it relates viscosity to molecular weight, which is useful for checking different batches of polymer in a production line to help ensure uniformity. 

Container Capacities, Fill Point Variation, Sterile Filter Monitoring, Start-Up Checks. These all can be checked easily on a statistical basis. The frequency of each check should be specified so that these become routine functions of quality control. Filler-bowl wine temperature fluctuations are extremely important since they may be a major cause of fill-point fluctuation in bottles. This fluctuation cannot be overemphasized because of legal ramifications. Specific standards of fill and head-space maxima are listed by the Bureau of Alcohol, Tobacco and Firearms in 27 CFR, part 4. 

Over recent years, there has been increasing emphasis upon quality control in the production of analytical data. This is hardly surprising, since there can be little point in performing an analysis if the accuracy of the determination is of no consequence. In most spectrometric methods there is considerable scope for producing poor results, because the methods are virtually all secondary methods, relying upon the accuracy of standard solutions for calibration. An error in the preparation of a litre of 1 mg 1"1 stock metal solution could result in years of data with a systematic error unless adequate checks are made. 

In most cases checking off the purity of a solvent does not necessitate tests for the various impurities instead, various solvent characteristics, physical constants sensitive to the presence of impurities are determined (conductivity, refractive index, boiling point, dielectric constant, infrared spectrum, NMR spectrum, etc.). In the case of non-aqueous solutions or solvents, the most important, and often the only specific analytical task, is the determination of the moisture content. In addition, the quality control of the solvent is based on the determination of various physical constants and the recording of characteristic spectra. 

In many instances, quality control consists of little more than visual inspection of a product to check for defects. This is a general and useful starting point for any quality-control function. Quality control is first and foremost a feedback process. When quality control is used to detect errors in the output stream, the information that it provides is used to adjust the manner in which the particular process treats the input stream. Determining the quality of the product (the output stream of the process) requires the creation of a product-specific system of quality-control testing and unequivocal methods of measuring designated features of the product, which can be compared with the ideal or standard features. 

Once the file has been exported into Aspen Dynamics, controllers are installed to achieve the desired control structure and dynamic simulations are mn to check the stability and performance of the control system. Various types of disturbances should be imposed on the system, such as throughput changes, feed composition changes, and changes in the set-points of the product-quality controllers (temperature and composition controllers). In this section we demonstrate, in a detailed step-by-step fashion, how these operations are performed in Aspen Dynamics. 

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