Checking performance

In many industries frequency and method of checking, together with accepted limits, will be determined by the standard operating procedure (SOP) adopted and may well be done on a daily basis. Regular performance checks are common sense. If a system is only checked once every 6 months and then found to be in error, 6 months work is suspect. 

The most common procedure is to run an indium standard under the normal test conditions and measure the heat of fusion value and melting onset temperature. These values are then compared with literature values and a check made against accepted limits. For many industries limits of 0.5°C for temperature or 1% for heat of fusion maybe accepted, though tighter limits of 0.3°C and 0.1% may also be adopted. The choice of limits depends on how accurate you need to be. Indium is the easiest standard to use because of its stability and relatively low melting point of 156.6°C, which means it can often be reused, provided it is not heated above 180°C. 

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Pressure gauges should always be fitted on the discharge side of liquid pumps, to check performance and give warning of a possible drop in flow resulting from dirty strainers. Manometer pressure gauges are required across air filters (see Chapter 2 7). 

Material balances are also useful tools for the study of plant operation and trouble shooting. They can be used to check performance against design to extend the often limited data available from the plant instrumentation to check instrument calibrations and to locate sources of material loss. 

The approximate method given below can be used to size an exchanger for comparison with a shell and tube exchanger, and to check performance of an existing exchanger for new duties. More detailed design methods are given by Hewitt et al. (1994) and Cooper and Usher (1983). 

Before the individual pieces of equipment are started, they should be checked out. Conoco, as part of its prestartup procedure, sent observers to the manufacturer s plant to observe the fabrication and to test the equipment before it was shipped. They found, among other things, at least 5 pumps with defective seals. These errors were corrected by the vendor before the items were shipped. This checking was in addition to checks performed during the construction phase. 

The final extract after evaporation may be partitioned with hexane in a separatory funnel to remove chlorophyll, lipids, carotenoids, and other fat-soluble materials (e.g., in avocado, olives, seeds), if considerable amounts of these compounds are present. However, possible loss of lipophilic polyphenolics should be checked. Performing the liquid-liquid extraction after the evaporation of solvent may reduce the amount of hexane required. The extract should be flushed with nitrogen gas and stored in the... 

CHECK performs a check on the logical consistency of the database. 

Check pretreatment unit operations The integrity of filters, softeners, tanks, and other pretreatment systems should be checked. Performance of each should also be evaluated and modifications made as required. 

Provide a brief description of the control checks performed at each stage of manufacturing and packaging of the drug substance. 

Pre-Startup Safety Review (PSSR) Audit check performed prior to equipment operation to ensure adequate PSM activities have been performed. The check should verify (1) Construction and equipment is satisfactory, (2) Procedures are available and adequate, (3) A PHA has been undertaken and recommendations resolved, (4) The employees are trained. 

In-Process Control EU (1991) Checks performed during production in order to monitor and, if necessary, to adjust the process to ensure that the product conforms to its specification. The control of the environment or equipment may also be regarded as part of in-process control. 

The provisional conclusion reached on the basis of checks performed so far is that, for molecules built up with atoms of the first and second row of the periodic table, a minimal basis set SCF wave function is... 

If there is any line in the map file that does not have six columns in the correct format, GenomeViz will show an error, point out the incorrect fine number and the column, and stop the plotting. In such as case, one must identify the error, correct it, and redo the plot again. The map file format is easy to maintain and modify in simple text editors or spreadsheets, and the extensive format checking performed by GenomeViz before plotting helps identify and correct mistakes before they are incorporated in the plot. The map file alone is sufficient for plotting numerical data, but both the map and tag files are needed to plot classification-type data. The type of data, qualitative or quantitative, is automatically detected from the map file. 

The sixth step in the design of an air monitoring survey is the development of a quality assurance and quality control plan. This plan should include specific sampling procedures, calibration procedures and frequency, sample custody, analytical procedures, data reduction, internal quality control checks, performance and system audits, completeness, and corrective action. 

IN-PROCESS TESTING Monitoring checks performed during production to ensure that the product conforms to its specifications. 

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