General test procedure

At the start of a test the cylinder is completely filled by the solid/liquid mixture which can exhibit the characteristics of a slurry, where both filtration and consolidation processes take place, or by a networked semi-solid where consolidation commences from the start of the test. In general the mixture will be concentrated and/or composed of fine particulates that do not settle appreciably under gravity. The piston is introduced to the open end of the cylinder and the constant applied force causes pressure to be generated within the cylinder. Liquid is expelled through the filter medium and collected in either a measuring cylinder or, in more sophisticated units, a vessel mounted on a load cell or electronic balance. The volume or mass of liquid is measured at various time intervals from the start of expression. The thickness of suspension (or cake towards the end of the test) in the cylinder can be calculated from a knowledge of the volume of liquid removed from the cylinder, or from measurements of the piston displacement from the beginning of the test should an appropriate transducer be fitted. 

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Three general test procedures used to measure the permeability of plastic films are the absolute pressure method, the isostatic method, and the quasi-isostatic method. The absolute pressure method (ASTM D 1434, Gas Transmission Rate of Plastic Film and Sheeting) is used when no gas other than the permeant in question is present. Between the two chambers a pressure differential provides the driving force for permeation. Here the change in pressure on the volume of the low-pressure chamber measures the permeation rate. 

If the rate law involves more than one species, as in equation 3.4-3, the same general test procedure may be used, but the integrated result depends on the form of the rate... 

There are standardised test procedures described in the pharmacopoeia (e.g., EP and USP) and in the standards referenced above. These are general test procedures developed and applicable for normal products. Testing products... 

A general test procedure that describes instrument standardization and analysis of various sample matrices, including liquid hydrocarbons, is found in the NIC instruction manual for the SP-3D [11]. A second, nearly identical procedure that is specifically designed for the analysis of mercury in liquid hydrocarbons may be foimd in UOP Method 938-00 [10]. 

Three general test procedures used to measure the permeability of plastics films are the absolute pressure method, the isostatic method, and the quasi-isostatic method. 

In the context of geotextile reinforcements, it is common to measure the installation damage that will be experienced during application. In general, test procedures to measure resistance to installation damage differ slightly in their approach, but some common features enable testing and research laboratories to accommodate the requirements established by all. 

The General Tests and Assays. This section of the USP gives methods for tests that are general in nature and apply to a number of the substances. Procedures are iacluded for such tests as heavy metals, melting point, chloride, sulfate, sterility, bacterial endotoxins, and pyrogens. Also iacluded are descriptions of various analytical techniques, such as spectrophotometry, chromatography, and nmr, and descriptions of tests to be used on glass or plastic containers, mbber closures, etc. 

Overall, the test methods pubhshed by INDA (Table 4) continue to be the general tests used to characterize fabrics however, specific market apphcations often generate special test procedures to fiilfill unique needs. 

Mechanical Properties. The performance of various polyester resin compositions can be distinguished by comparing the mechanical properties of thin castings (3 mm) of the neat resin defined in ASTM testing procedures (15). This technique is used widely to characterize subtle changes in flexural, tensile, and compressive properties that are generally overshadowed in highly filled or reinforced laminates. 

In general, textile materials are moisture- and temperature-sensitive. As a result, all tests should be performed at ambient conditions of 21°C and 65% relative humidity unless otherwise stated. Most of the testing procedures discussed for textile materials are available in the Hterature (1,2). 

The well-known Gibbs-Duhem equation (2,3,18) is a special mathematical redundance test which is expressed in terms of the chemical potential (3,18). The general Duhem test procedure can be appHed to any set of partial molar quantities. It is also possible to perform an overall consistency test over a composition range with the integrated form of the Duhem equation (2). 

General References AIChE Testing Procedures Crystallizers, American... 

Note We have discussed the test procedures and tolerances in general terms. For more accurate test methods and tolerances see lEC 60529. 

The test procedure and test equipment is almost the same as for number 5 and generally as below ... 

The tests against step numbers I, 2 and 3 in Section 14.2,2 are of a general nature and no test procedure is prescribed. The rest are similar to the tests covered under type tests. The procedures of tests and requirements of test results will remain the same as discussed earlier. 

Additional tests on a capacitor VT The tests discussed above refer generally to the electromagnetic unit only. To test the whole VT, the following tests are recommended. For the test procedure and results refer to lEC 60186. 

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