Service testing

The modern Russian MIA flaw detectors use pulse version of the method [1-3], which peirnits to produce very portable (0.7 - 1.5 kg) and simple instruments, convenient especially for in-service testing. The objects to be tested are multilayer structures of reinforced plastics, metals and other materials honeycomb panels, antenna fairings, propellers, helicopter rotors and so on. In mentioned instruments amplitude-frequency analog signal processing is used. 

The Federal specifications stipulated that only those asphalts that had been demonstrated by service tests as satisfactory for the intended use would be accepted. The specifications also indicated the type and location of constmction and the relative amount of traffic for each of the grades. The AASHTO specifications indicated that the use of each grade depended on the type of road, climate, and traffic. The ASTM suggested the type of constmction for which each grade would be used. 

Each trolley is recommended to possess three distinct positions of movement, as shown in Figure 13.36. i.e. service , test and isolation ... 

Clearance and ereepage distances must be maintained in the service, test and isolated positions. 

Recognizing the flexibility of the affinity laws, it is better to select an original pump impeller diameter that is somewhat larger than required for the range of anticipated performance, and then cut this diameter dowm after in-service tests to a slightly smaller diameter. This new performance can be predicted in advance. Once the impeller diameter is too small, it cannot be enlarged. The only solution is to order the required large impeller from the manufacturer. 

Service tests, in which the test specimens —which may often take the form of manufactured components —are exposed to the particular conditions in which they are to be used, e.g. in process streams of chemical plant. 

Service tests will be used (1) where the operating conditions cannot be successfully reproduced in laboratory tests, (2) where the environment does not occur naturally, (3) where real components, as opposed to test specimens, need appraisal, and (4) to confirm laboratory and/or field tests. 

The corrosion testing of metals in natural waters is most usually conducted in field or service tests since the conditions of flow are important and often rate-determining. Testing will be concerned with mains water (potable water), river-water and sea-water or combinations of these as in estaurine conditions. Test specimens of various geometries will be used, e.g. in the... 

In considering exposure tests, whether in the form of laboratory, field or service tests it is important to consider the purpose of the test and the relevance of the data to the anti-corrosion function of the coating. Thus, in the case of paint coatings, factors such as gloss deterioration, chalking and colour retention are of considerable importance in some industries, for example the automotive industry, but perhaps of minor importance in the painting of structural steelwork. These assessment factors can nevertheless be of significance since they may be the precursors of corrosion of the basis metal. 

These laboratory tests may be followed by engine dynamometer tests (BS5117 Section 2.4 1985(1989)) and finally by road tests in working vehicles (BS 5117 Part 2 Section 2.5 1985 (1989)), thus completing the sequence of laboratory, field, service testing. 

Test and Evaluation Command responsible for environmental test centers, proving grounds, and the former Continental Army Command service test centers... 

Natural environmental exposure, the exposure of materials or products to natural environmental conditions, can be regarded as a form of simulated service testing. Such exposures provide information on the durability of the material without the effects of such factors as fatigue and abrasion. 

Estimates of service life are usually made either by natural or simulated trials or, most commonly, by accelerated tests with extrapolation to predict performance at longer times under less severe conditions. An alternative approach is to subject the product to environmental exposures which equate to the whole design life, and then to assess performance by real or simulated service tests (the end performance assessment). The exposures usually have to involve accelerated procedures and can be composed of several environmental agents applied simultaneously or sequentially. 

NFPA 1911 —Standard for Service Tests of Pumps on Fire Department Apparatus... 

NFPA 1911 Standard for Service Tests of Fire Pumps Systems on Fire Apparatus... 

NFPA 1962 Standard for the Care, Use, and Service Testing of Fire Hose... 

Service Test Type. Materiel which has performed satisfactorily in engineering tests and is authorized ro be procured in limited quantity for user test (See Note 1 below)... 

Service test-A test in which the product is evaluated under actual service conditions. 

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