Conductivity testing

As part of TSCA, EPA can require the testing of any chemical if there is the possibiUty of an unreasonable risk to health or environment or if there is significant human or environmental exposure. If the substance poses an unreasonable risk, EPA can prohibit the manufacture, processing, or distribution of the substance limit the amount of the substance that can be manufactured, processed, or distributed prohibit a particular use for the substance limit the concentration of the substance during manufacture, processing, or distribution regulate disposal methods for the substance and require manufacturers to maintain records of process and to conduct tests to assure compliance with EPA rules. 

Selection of Equipment If a new product is being considered, the preliminaiy study must be highly detailed. Laboratory or pilot-plant work must be done to establish the controhing factors. The problem is then to select and instaU equipment which 1 operate for quantity production at minimum overall cost. Most equipment vendors have pilot equipment available on a rental basis or can conduct test runs in their own customer-demonstration facilities. 

This test is basically quahtative and can be used for identifying exothermic reactions. Like the DSC, it is also a screening test. Reported temperatures are not rehable enough to be able to make quantitative conclusions. If an exothermic reaction is observed, it is advisable to conduct tests in the ARC. 

For conducting tests in pipe lines of 75-mm (3-in) diameter or larger, a spool holder as shown in Fig. 28-21, which employs the same disk-type specimens used on the standard spool holder, has been used. This frame is so designed that it may be placed in a pipe line in any position without permitting the disk specimens to touch the wall of the pipe. As with the strip-type holder, this assembly does not materially interfere with the fluid through the pipe and permits the study of corrosion effects prevailing in the pipe line. 

Perform conductivity tests on slurry before feed to filter... 

All the CT (current transformer) secondaries must be shorted and grounded while conducting the test on the main circuit. This condition is redundant while conducting test on the auxiliary circuit. 

When a voltage is applied to a dielectric (insulator), a current passes that decays with time owing to various polarization mechanisms [ 133]. Conductivity is always time-dependent. This general time dependency affects conductivity measurement for nonconductive liquids, where the peak initial current is used to calculate conductivity. Test methods are given in 3-5.5 and... 

As part of the verification plan, you should include an activity plan that lists all the planned activities in the sequence they are to be conducted and use this plan to record completion and conformance progressively. The activity plan should make provision for planned and actual dates for each activity and for recording comments such as recovery plans when the program does not proceed exactly as planned. It is also good practice to conduct test reviews before and after each series of tests so that corrective measures can be taken before continuing with abortive tests (see also under Design validation). ... 

The manufacturer will, on request of the purchaser, conduct tests as called for in specifications on reasonable notice from the purchaser. During the tests, the manufacturer will afford opportunity to the purchaser s representative to present. 

Industrial atmospheres usually accelerate the corrosion of zinc. When heavy mists and dews occur in these areas, they are contaminated with considerable amounts of acid substances such as sulphur dioxide, and the film of moisture covering the metal can be quite acid and can have a pH as low as 3. Under these conditions the zinc is dissolved but, as the corrosion proceeds, the pH rises, and when it has reached a sufficiently high level basic salts are once more formed and provide further protection for the metal. These are usually the basic carbonate but may sometimes be a basic sulphate. As soon as the pH of the moisture film falls again, owing to the solution of acid gases, the protective film dissolves and renewed attack on the metal occurs. Hudson and Stanners conducted tests at various locations in order to determine the effect of atmospheric pollution on the rate of corrosion of steel and zinc. Their figures for zinc are given in Table 4.34 and clearly show the effect which industrial contamination has on the corrosion rate. 

The need for temperature cycling should be taken into account when designing or conducting tests. The nature of the test vessel should be considered for tests in aqueous solutions at temperatures above about 60°C since soluble constituents of the test vessel material can inhibit or accelerate the corrosion process. An inhibiting effect of soluble species from glass, notably silica, on the behaviour of steel in hot water has been shown . Pure quartz or polymeric materials are often more appropriate for test vessel construction. 

Designers unfamiliar with plastic products can use the suggested preliminary safety factor guidelines in Table 2-11. They provide for extreme safety. Any product designed with these guidelines in mind should conduct tests on the products themselves to relate the guidelines to actual performance (Chapter 4, RP PIPES, Stress-Strain Curves). With more experience, more-appropriate values will be developed targeting to use 1.5 to 2.5. After field service of... 

The purity of steam can be measured by an increase in electrical conductivity. Testing for sodium ions (Na+) is particularly useful because almost without exception, all BW contains sodium ions. 

These tracer and tagged polymer products are very useful for conducting test work such as in the examples given above, but, similar to their application in cooling water, the monitoring system only measures the bulk-water concentration of polymer. This may have little or no relevance to metal surface chemistry and the protective integrity of the magnetite film. 

But I think we have the tools in behavioral pharmacology to conduct tests in rats that will be sensitive to serotonin depletion. And I assume that those can be extrapolated to primates. 

Software producers must fulfill the requirements for development, testing, and documentation. When the user is confident that these requirements have been met, and the system functions adequately to fulfill his or her needs, the user must perform validation prior to placing the software in service. An analytical laboratory is an example of an end-user that conducts testing prior to software/computer system installation. 

Conductivity test Immerse a pair of electrodes connected to an external electric source in the emulsion. If the external phase is water, a current passes through the emulsion. If the oil is the continuous phase, the emulsion fails to carry the current. 

---