Measurements routine checks

The evaluation methods could be direct, e.g., measuring a containment index, or indirect, e.g., measuring pressure loss or velocity distribution. The direct methods are used to measure the performance of a hood or an inlet during periodic preventive maintenance. Indirect methods are used for verifying or checking on a daily basis (routine checks). How often each method is used depends on the availability of instrumentation and qualified personnel, since direct measurement of a hood s performance can be both expensive and difficult. On the other hand, indirect methods are usually easier to use and can sometimes include inexpensive, continuously monitoring instruments (pressure gauges or velocity indicators). 

Although measurement of the compressive strength of agglomerates is certainly more convenient for routine checking and quality control, the tensile strength is a more fundamental property, since in theory it can be... 

A frequently discussed question is whether either system suitability testing or the analysis of QC samples are sufficient to prove ongoing system performance, or whether additional checks should be performed. The answer to this question depends very much on the conditions under which the control samples are analyzed. For example, if the system is used for trace analysis and the amounts of the control sample do not include trace-level amounts, the capability of the system to measure low amounts should be verified. In HPLC, this could be a routine check of the wavelength accuracy, the baseline noise, and the intensity of the UV lamp. System suitability checks and control sample analysis are sufficient as PQ checks if all critical system parameters are checked as part of tests and evaluations. 

There is no cure for viral diseases. Remove and destroy infected plants immediately. Wash tools and hands after working around diseased plants. To limit the spread of viruses, routinely check lilies for aphids, and control the pests if necessary see Leaves, stems, and buds distorted, sticky clusters of small insects above for control measures. Buy bulbs and plants from reputable sources—some will certify stock as virus-free. Do not phint lilies in sites where diseases have occurred on bulbous plants. Separate lilies from tulips, cucurbits, and wild lilies. 

The rheological properties of slips are usually measured by rotary viscomete while capillary viscometers are used for routine checks. 

UVA lS-spectroscopy is commonly used in the quality control laboratories of the flavour industry particularly for those products where colour characteristics are important. The possible measurement of the absorption or transmission of the samples in wavelength maxima as well as the intake of a spectrum over the entire wavelength area between 250-800 nm is important for the routine check of colour identity. By constant measuring parameters (cuvette, dilution, etc.) exact evidence of the colour intensity can be established. This analysis is very important for coloured flavouring preparations, fruit- and plant extracts or essential oils with colouring properties, as well as for testing for the presence of non permitted colouring materials [1],... 

When converting laboratory-based assays to on-line assays, it is important to use the simplest technology that fulfils the requirements, to use analysers that can automatically perform calibration and routine checks where possible and to use those that may even be able to monitor other analyser operations. The number of sampling points in the process to be measured must be decided, as must the exact monitoring locations. It is important that only relevant information should ever get to the operator and, as far as possible, changes made to the process based on analytical results should be taken care of in the background. 

Incidentally, by using a quality card (control chart) your professional eyes will immediately see if it is time for the next routine check and preventive measure. You could enter the actual peak height as a function of time (day, week), the ratio of peak area to peak height, maybe at two wavelengths. This can show up interesting trends. 

Mass, dimensions, and density are also important in the factory, being factors in the costing of products and in quality control, from routine checking on dimensional accuracy of components to a simple control measure for the consistency of polymer compounds. 

The final problem at this level is that routines are dynamic chains of behaviour and not static ones. There is a constant tendency to streamline them and to drop steps which appear unnecessary. The most vulnerable steps are the routine checks for very infrequent problems in very reliable systems (e.g. tapping the face of a modern measuring instrument to check that the needle has not stuck). 

Apart from the normal routine checks, one would have to assure oneself that the electronic system was working satisfactorily - at high count rate, there is the additional burden of confirming that counting losses are being adequately accounted for. There are procedures that have been widely used for many years. In 1990, Gehrke proposed the particular procedure below, which is now enshrined in the US standards ANSI N41.14 (revised). It is a test of the precision of automatic or semi-automatic dead time correction of whatever type - by a measured correction factor, by PUR and ETC circuits, by the pulser method, by the virtual pulser, or by any combination of these. The procedure is as follows ... 

Ultraviolet and Infrared Radiation Monitoring Devices. A variety of instruments are commonly used to measure ultraviolet and infrared radiation.They are classified according to the type of detector used, which is generally one of two types thermal detectors or photoelectric detectors. Thermal detectors are those in which the absorbed radiation is degraded to heat and subsequently converted to an electric signal by changing the electric resistance of a filament. Photoelectric detectors are based on the principle that the absorbed photons eject electrons from a material. Most of these instruments are precalibrated by the manufacturer, but should be routinely checked prior to field use. 

The measurement precision by the FUMI theory would be useful for circumventing the above-mentioned problem in the present FIA-ECD. In order to verify the precision of measurements, the FUMI theory can be applied to provide the present FIA-ECD. Theoretical RSDs predicted by the FUMI theory were compared with an experimentally observed RSD by repetitive measurements. Precision profiles of citric acid were examined as an example. The experimentally observed RSD at 0.05 mM was 2.1% ( = 6). Meanwhile, the theoretical predicted RSD of citric acid at 0.05 mM was 1.6%. This value was within the 95% confidence interval of the statistically obtained RSD at 0.05 mM citric acid (m = 6), ranging from 1.3% to 5.2%. Thus, it was found the measurement precision by ISO 11843-7 is applicable to estimate the precision in FIA-ECD without repeated measurements of real samples. The present assessment strategy using the prediction of measurement precision by ISO 11843-7 is useful for routine checks of FIA-ECD, saving not only considerable amounts of chemicals but also experimental time. 

Two types of measurements of effort, routine checks and management systems audits, are described in the following section. 

FIGURE 4.5 Management system elements of ISO s 14001 and OSHA s VPP MEASUREMENTS OF EFFORT—ROUTINE CHECKS... 

Analysis of past and current values of measured variables can provide valuable diagnostic information for the detection of abnormal events. As described in Section 10.1, on-line measurements are routinely checked to ensure that they are between specified high and low limits and to ensure that the rate of change is consistent with the physical process. Also, a simple calculation can identify a common type of sensor malfunction or fault. 

Elemental analysis of the bulk components in a catalyst is measured by X-ray fluorescence (XRF), which has now replaced traditional wet analysis. If required, electron probe analysis can also provide information on the distribntion of elements in a catalyst particle. Bnlk phases in a catalyst and crystallite size are determined by X-ray diffraction (XRD), as either a routine check or a diagnostic procedure to examine catalysts damaged dnring operation. 

During validation, the relationship between response and concentration is established. Checks also are made to ensure that the linearity of the method does not make too large a contribution to the measurement uncertainty (the uncertainty due to the calibration should contribute less than about 20% of the largest uncertainty component). The calibration schedule required during routine operation of the method is also established. It is wise to carry out sufficient checks on some or all of the following performance parameters, in order to establish that their values meet any specified limits. 

The approaches described above give approximate values for the LoD and LoQ. This is sufficient if the analyte levels in test samples are well above the LoD and LoQ. If the detection limits are critical, they should be evaluated by using a more rigorous approach [1, 2, 14]. In addition, the LoD and LoQ sometimes vary with the type of sample and minor variations in measurement conditions. When these parameters are of importance, it is necessary to assess the expected level of change during method validation and build a protocol for checking the parameters, at appropriate intervals, when the method is in routine use. 

Method validation provides information concerning the method s performance capabilities and limitations, when applied under routine circumstances and when it is within statistical control, and can be used to set the QC limits. The warning and action limits are commonly set at twice and three times the within-laboratory reproducibility, respectively. When the method is used on a regular basis, periodic measurement of QC samples and the plotting of these data on QC charts is required to ensure that the method is still within statistical control. The frequency of QC checks should not normally be set at less than 5% of the sample throughput. When the method is new, it may be set much higher. Quality control charts are discussed in Chapter 6. 

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