Accuracy checking

What is a control sample and how is it useful as an accuracy check ... 

As another phase of the ongoing quality control program, method accuracy for waste water samples must be assessed and records must be maintained. After the analysis of five spiked waste water samples as in the accuracy check just described, the average (P) and the standard deviation of the percent recovery (sp) are calculated. The accuracy is expressed as a percent interval or range from P — 2sp to P + 2sp. The... 

It is important to acknowledge that the maintenance of existing software can account for over 70% of all effort expended by a software organization. Refer to Figure 8-2. The computer hardware suppliers normally recommend minimum maintenance schedules including accuracy checks for their components.3... 

An accurate reproduction of the master production record, checked for accuracy, dated, and signed. An investigator will verify that controls exist to make sure that the batch record issued is reproduced from the correct master copy. If a master record changes, there must be some type of documented purging of the files (electronic and/or paper). Additionally, at the time of issuance of a batch record, there must be a documented check for accuracy. This accuracy check should include that all pages issued are complete (no printer or photocopy errors) and that the correct revision of the master was used. 

If the values of ni are repeating themselves within reasonable accuracies, check the energy equailofi with these ni and the trial temperature estimated. 

An approximate accuracy check is possible using the SEC and TDS determinations. The TDS (in milligram per litre) should be between 0.55 and 0.75 times the SEC (in microsecond per centimetre) for most waters up to a TDS of a few thousand milligrams per litre. Water in which anions are mosdy dominated by bicarbonate and chloride should have a factor near the lower end of this range, whereas waters high in sulphate may reach or even exceed the upper end. For repeated analyses from the same area, a well-defined relationship can often be established. 

It should be recognized that automated name recognition provides a realistic alternative to optical structure recognition in many cases. Indeed, the two techniques are complementary there are many cases where either no name is given (particularly common with complicated structures) or the name is insufficiently precise to convey the full structural information (including stereochemistry). The ideal system would incorporate both techniques and use either whichever is more appropriate in a given situation, or even both in parallel to provide an accuracy check. 

No qualification protocols defining testing or acceptance criteria were apparent. Accuracy checks, input-output checks, and alarm testing measures were inadequate. Change and version control measnres for software were inadequate. 

Electronic records are copied, possibly reprocessed, to make them accessible by a new computerized archive system. This can be a large and complex task but has the advantage that the new system is specifically designed for the purpose. This method, however, should not be used where the integrity of the original records being migrated can be disputed, unless data accuracy checks are implemented. Data load requirements are discussed in Chapter 11. 

Note that the interaction WOE score is based on judgment the weaker the evidence, the closer the score is to zero, and the less impact the interaction has on the estimated mixture response. Eor most mixtures, no data exist on the whole mixture, so that accuracy checks are usually not possible. As a consequence, the quality of the component-to-mixture extrapolation is then judged by the quality and relevance of both the component data and pairwise interaction data. 

Figure 12. The ratio Ci /C2 computed for a very rare event in contrast to the system in Fig. 10. For the rare event it is difficult to do the exact calculations. Therefore, accuracy check was done for not so rare events. Error bars are calculated by adding the standard errors for each factor in the numerator and denominator, each of which is given from the standard error of the mean from 20 uncorrelated runs. Here the potential is y = 10 , y = 10 (for Hi), and y = 1.2 x 10 (for H2). kT is 0.1. Since y is 10 and kT is 0.1, it takes only t 0.01 to get across the channel. But after time Z = 1, the probability of a reaction is only 0.0001.

Most dispensers and diluters can operate to a high degree of precision but, since they contain mechanical parts liable to wear, should be regularly overhauled and their accuracy checked at frequent intervals. A major source of error in diluters, particularly when very small volumes of sample are being diluted, is that any variation in the shape and size of the meniscus at the tip of the sampling pipet, when the sample container is removed, will impair both the accuracy and precision of the dilution. Any damage to the tip of the pipet must be rectified immediately, and necessarily implies replacement of the pipet and recalibration of the instrument. 

Accuracy checks are generally performed by comparing measured data with data from certified reference materials. When measured data are not accurate because of relative or systematic errors, or a lack of precision (noise), the comparison between measured data and reference values cannot lead to any useful conclusion in an expert system. To process larger sets of potential source data for knowledge bases, a method must be used that takes inaccuracies as well as natural fuzziness of experimental data into account — ideally automatically and without the help of an expert. 

Column oven Temperature accuracy Check actual column oven temperature with validated thermal probe 30 + 2°C 50 2°C... 

Special thanks go to Professor Dorothy B. Kurland for her exceptionally thorough accuracy check of the entire text. And I extend my gratitude to all the other professors who reviewed portions of this first edition or participated in our developmental survey process to assess the content needs for the text ... 

The number-size distribution of ambient particles was monitored by an optical particle counter (OPC) (RION, KC-OID). Information concerning the accuracy of the OPC s size determination was checked by the manufacmrer (RION). The four-step known size monodisperse polystyrene type latex (PSL) spheres (0.294, 0.505, 1.001, and 2.106 pm) were employed. The OPC sizing accuracy check was conducted by sampling of these PSL particles. In the field measurement, OPC was operated at intervals of every 30 min. The flow rate for the OPC was 3 X 10 m h During the sampling period, the ranges of temperature and relative humidity (RH) were 12.8-28.4 °C and 30-79%, respectively. 

The determination of water content of soil by microwave oven has been standardized by the ASTM D4643. This test is not intended as a replacement for ASTM D2216 (mechanical convection oven method) but, rather as a supplement when more rapid results are required or desired to expedite other phases of testing. ASTM D2216 (mechanical convention oven method) is used to compare with for accuracy checks and correction. 

Accuracy Check and Class Test Cindy Berrie at the University of Kansas worked closely with the author, checking his work and providing detailed feedback as she and her students did a two-semester class test of the manuscript. The students also provided the author with comments on how to improve the manuscript so that the presentation of content was compatible with their variety of learning styles. 

A select group reviewed text and art manuscript in draft and final form, reviewed page proofs in first and revised rounds, and oversaw the writing and accuracy check of the instructor s solutions manuals, test bank, and other ancillary materials. 

In a so-called preperiod, one or several control sample(s) of every analysis series are analyzed together with the samples. For each control sample, a precision check and, if possible, an accuracy check are carried out by comparison with given values. If the analysis quality is acceptable, warning and intervention limits are defined and the quality control card is drawn. In the subsequent control period, compliance with the defined limits is monitored by measuring further control samples. The results from these control analyses or the statistical quantities derived from them are continuously registered in the quality control card. The abscissa relates to the continumg serial number, whereas control values are registered on the ordinate. 

Preemployment tests—examinations administered by potential employers to determine applicants job qualifications and readiness examples include the Bennett Mechanical Comprehension Test (BMCT) by George K. Bennett (S T version) the Richardson, Bellows, Henry Company "Test of Chemical Comprehension" (S T version, 1970) and the California Math Test. Types include reading comprehension, accuracy checking, block counting, and tests developed in-house. 

Accuracy Checkers Ten professors participated in accuracy checking at each stage of the manuscript development and proof process to ensure that the end product is as error-firee as possible. 

Check all control valves for operation and flow Check all pilot positions for accuracy Check auxiliary control devices... 

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