Testing apparatus

Tunnel Test. The tunnel test is widely used to test the flame spread potential of building products such as electrical cable (15) and wall coverings (16). The test apparatus consists of a tunnel 7.62 x 0.445 m x 0.305 m ia cross section, one end of which contains two gas burners. The total heat suppHed by the burners is 5.3 MJ/min. The test specimen (7.62 m x 50.8 cm), attached to the ceiling, is exposed to the gas flames for 10 minutes while the maximum flame spread, temperature, and smoke evolved are measured. The use of this and other flame spread test methods has been reviewed (17). 

Evaluations have been conducted using deer, a multiple-choice preference-testing apparatus, and tetramethylthiuram disulfide [137-26-8] (TMTD) (29) or the fungicide thiram as a standard repeUent for competitive tests with repeUent-treated food (78). 

Flammability—Flash Point The closed-cup flash point determination produces the most important data to determine the potential for fire. The flash point is the lowest temperature at which the vapors can be ignited under conditions defined by the test apparatus and method. 

In all of these tests, flame acceleration was minimal or absent. Acceleration, when it occurred, was entirely due to intrinsic flame instability, for example, hydrodynamic instability (Istratov and Librovich 1969) or instability due to selective diffusion (Markstein 1964). To investigate whether the flame would accelerate when allowed to propagate over greater distances, tests were carried out in an open-sided test apparatus 45 m long (Harris and Wickens 1989). Flame acceleration was found to be no greater than in the balloon experiments (Table 4.1a). 

The flash point of a fliumiiable liquid is defined as Uic teinperature at which Uie vapors can be ignited midcr conditions defined by the test apparatus and iiieUiod employed. The Uirec major iiieUiods of measuring Uic flash point are ... 

Priif-anstalt, /. testing laboratory, -apparat, m. testing apparatus, tester, -arbeit, /. testing, assaying, checking experimenting. 

FPN No. 2) The gas subdivision in (a), (b), and (c) above is based on the maximum experimental safe gap, minimum igniting current, or both. The test apparatus for determining the maximum experimental safe gap is described in lEC Publication 79-lA (1975) and UL Technical Report No. 58 (1993). 

Load Testing Apparatus. The load apparatus used to simulate the working load on the test unit shall be calibrated in accordance with ASTM E-4 Standard Methods of Verification of Testing Machines, so as to assure that the prescribed test load is obtained. 

The flash point of an oil is the temperature at which it gives off, under specified conditions, sufficient vapor to form a flammable mixture with air. This is very different from the temperature of spontaneous combustion. The test is an empirical one and the result depends upon the instm-ment used and the prescribed conditions. For example, the flash point may be closed or open , depending on whether the test apparatus has a lid or not. As far as lubricating oils are concerned, the test is of limited significance, although it can be indicative of contamination (for example, the dilution of crankcase oil by fuel). 

Campbell points out that in evaluating condenser tube materials a test apparatus is required that will include all the principal hazards likely to be encountered in service and should thus cater for the following conditions impingement, slow moving water, heat transfer and shielded areas. Furthermore, the internal surfaces should not be abraded, as in the jet impingement test, but should be tested in the as-manufactured condition, particularly in view of the deleterious effect of carbon films produced during manufacture (see Sections 1.6 and 4.2). LaQue has pointed out the importance of specimen area in impingement tests... 

Fig. 19.23 Campbell test apparatus for determining the various forms of attack that condenser-tube materials are subjected to in service (after Campbell...

Vibratory test apparatuses are relatively cheap to build and run, and have low power consumption, while flow rigs are bulky, expensive to build and run, and have high power consumptions but have the advantage that they simulate more closely practical conditions of hydrodynamic cavitation. On the other hand, the damage rate is higher in the vibratory tests than in the... 

The stress-relaxation behavior of a material is normally determined in either the tensile or the flexural mode. In these experiments, a material specimen is rapidly elongated or compressed to produce a specified strain level and the load exerted by the specimen on the test apparatus is measured as a function of time. Specimens of certain plastics may fail during tensile or flexural stress-relaxation experiments. 

The conditioned specimens are cantilevered from the sample holder in the test apparatus, which has been brought to a low temperature (that at which the specimens would be expected to fail). When the... 

Figure 2. Closeup view of tensile test apparatus showing (A) Robotic arm with special fingers...

CeU type Test apparatus Exposme level References... 

The variations in testing apparatus, insect species, dosages, exposures, and criteria of activity render difficult the appraisal of individual or groups of insecticides. 

The test apparatus chosen for disintegration testing and dissolution testing should be one of those described in the Ph Eur unless another pharmacopoeial or a noncompendia method can be justified. The test conditions and the proposed release rates should be justified in terms of batch reproducibility. 

A Shah, C Peot, J Ochs. Design and evaluation of a rotating filter-stationary basket in vitro dissolution test apparatus I Fixed fluid volume system. J Pharm Sci 64 671, 1973. 

Figure 8.3 Schematic diagram of a tensile testing apparatus...

Figure 8.18 Schematic iiiustratfon of abrasive wear resistance testing apparatus...

Public information about the specific chemical identity of the surfactants and stabilizers in use is scant(353-355) (Figure 11). Performance of foamed fluids is heavily dependent upon the size and distribution of the individual foam cells that are present, therefore the generator, testing apparatus, pressure and procedures employed are critical parts of the evaluation and the observed results. Contaminants (salts, acids, alkalies, etc) in the liquid phase also can cause drastic changes in foam performance. 

The chemistry involved in this explosively unstable system is reviewed [1]. The mechanism of the trigger reactions that initiate the exothermic decomposition of chlorate-sulfur mixtures has been studied. Mixtures containing 1-30% of sulfur can decompose well below the m.p. of sulfur, and addition of sulfur dioxide, the suspected chemical trigger, causes immediate onset of the reaction [2], Autoignition of stoichiometric mixtures can be as low as 115°C, with frictional sensitivity at 5N, the lowest load the test apparatus permitted. Both were dependent upon the history of the sulphur used [3],... 

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