Standard precision

The precision values referred to in 1 (iii) shall be obtained from a collaborative trial which has been conducted in accordance with an internationally recognised protocol on collaborative trials (e.g. International Organisation of Standardization Precision of Test Methods )17 The repeatability and reproducibility values shall be expressed in an internationally recognised form (e.g. the 95% confidence intervals as defined by ISO 5725/1981). The results from the collaborative trial shall be published or be freely available. 

INTERNATIONAL ORGANIZATION FOR STANDARDIZATION, Precision of Test Methods - Standard 5725, Geneva, ISO, 1981 (revised 1986 with further revision in preparation). 

Table XII. Precision on NBS—EPA Round-Robin Gasoline Sample Counting Standard Precision ...

The secondary gas standards are blended using the same apparatus as that employed to prepare the primary gravimetric standards. Precise measurements of the gas pressure and gas mass are carried out at each stage in the process and these enable the concentrations of the mixtures to be produced to within 1% of the concentration of the appropriate NPL primary standards. Up to three mixtures with the same nominal concentrations can be produced together. The mixtures are subjected to stability checks before their concentrations are certified with respect to NPL primary standards. 

From the viewpoint of the mechanical characteristics, glass and silicon resemble each other. They have a similar mechanical hardness, are brittle as they lack plasticity and are thus prone to fracture. Of the standard precision engineering procedures available for shaping, only those that do not use a geometrically defined cutter can be used, such as grinding and lapping. Microengineering techniques are much more efficient, but they do prove difficult for deeper structures. 

Table IV Standard Precise 494 Sequencer - Signal Enhancement based on ratio of the observed pmoI/mAU for the 494HT verses the 494HS...

Other technical problems, such as heterophilic antibody (HAMA) interference, may limit the clinical value of Tg measurements. Recommendations regarding approaches to standardization, precision, limits of detection, and hook effects have been suggested. Serum Tg values obtained by different methods are usually not interchangeable, and the same assay should be used to perform serial serum Tg measurements in a patient. When a change in method is made, the laboratory should define performance characteristics of the new method and validate its clinical utility before implementing the method for patient care. 

The highest precision for quantitative GC is obtained using internal standards because the uncertainties introduced by sample injection, flow rate, and variations in column conditions are minimized. In this procedure, a carefully measured quantity of an internal standard is introduced into each standard and sample (see Section 8C-3), and the ratio of analyte peak area (or height) to internal-standard peak area (or height) is used as the analytical parameter (see Example 31 -1). For this method to be successful, it is necessary that the internal standard peak be well separated from the peaks of all other components in the sample. It must appear close to the analyte peak, however. Of course, the internal standard should be absent in the sample to be analyzed. With a suitable internal standard, precisions of 0.5% to 1 % relative are reported. 

A four-probe apparatus was used for a c measurements on pressed pellets, (f> 20 mm, thickness 150 pm, (pressed under a pressure of a 3.2 kbar). measurements were carried out using a network analyser (HP 8720) working between 130 MHz and 20 GHz with a 50 fi line. Powder samples were pressed (3,2 kbar) in order to give die castings compatible with APC7 standard. Precision of the measurements was about 5% for e values. 

Isotope data for saturated (sat) and aromatic (aro) hydrocarbon fractions are in parts per thousand (%c) relative to the PDB belemnite standard. Precision is about 0.05%o. 

As in the case of dispersive Raman spectrometers (cf Section 4.4.1), it is necessary to calibrate the wavelength scale of dispersive UV/VIS spectrometers. The most accurate standards for checking the UV/VIS wavelengths are lasers of various types. The inexpensive helium-neon laser can be used to check at 632.8 nm. For spectrometers with a deuterium source, spectral lines at 486.6 and 656.1 nm can be used for calibration. A common method for wavelength calibration is the use of optical filters. A filter of didymium glass has many sharp absorption peaks, which can be used as a second wavelength standard (precision within 0.5 nm). 

In the current standard precision practices for ASTM and ISO, repeatability and reproducibility are defined as intervals or upper and lower limits within which a measured value is expected to fall on the basis of the t distribution at some confidence level. From the development in Section 3.5. the absolute difference between two means f - i l is given by... 

Standards like the lEC 61508 (1998-2005) propose a succession of tasks to develop safety critical systems. Nevertheless, these standards precisely define the analysis to produce but do not provide methods to efficiently conduct them. Therefore, there is a real need in today s industry to obtain tools and methods to support the design of safety critical systems, by linking classical methods of each specialist working on those projects. 

Next is setting the docking parameters. First is precision, where we can find three options high-throughput virtual screening (HTVS), standard precision (SP), and extra precision (XP). HTVS rapidly screens very large number of compounds and cannot score in place. SP is the default step where we can screen a laige unknown... 

Special calibration samples consist of a plastic material immersed in liquid paraffin to give percentages of solids of approximately zero, 35 and 70. These must be standardized precisely before being used to calibrate the pulse NMR spectrometer. The pulse NMR spectrometer must first be checked by means of the calibration samples. If the values are found to deviate by more than 0.3% the instrument should be adjusted. The standard deviation of the pulse NMR spectrometer should always be smaller than 0.3% solids. 

Instrumentation—All instruments and measuring devices used must be approved by an electrical engineering and/or instrumentation technician prior to use. Special considerations must be given to standardization, precision and accuracy, calibration requirements and maintenance. All original manuals and specifications shall be provided. 

The molecular docking was performed using standard precision protocols with default parameters. The docking poses were ranked by their glide scores, and the best predicted conformation in each system was nsed for the subseqnent molecnlar dynamics simulation and binding energy analysis. 

FIGURE 2-10 Standard precision roller chain with bent attachments for conveyor service. 

Table 2.51 IRMS primary reference materials for irm-GC-MS. Absolute isotope ratios R in 1 o standard precision.

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