Testing chamber

Metal deck assembhes are tested by UL for under-deck fire hazard by usiag their steiaer tunnel (ASTM E84). The assembly, exposed to an under-deck gas flame, must not allow rapid propagation of the fire down the length of the tuimel. FM uses a calorimeter fire-test chamber to evaluate the hazard of an under-deck fire. The deck is exposed to a gas flame and the rate of heat release is measured and correlated to the rate of flame propagation. A different FM test assesses the damage to roof iasulations exposed to radiant heat. 

A second snag test method, described by ASTM D5362, is the bean bag snag test. Each fabric specimen is made into a cover for a bean bag, which is randomly tumbled for 100 revolutions in a cylindrical test chamber fitted on its inner surface with rows of pins. Evaluation is similar to that for the mace snag test. 

The te.st is carried out by using an apparatus shown in Figure 11.8, consisting of a closed test chamber in which talcum powder can pass through a sieve having square openings of 75 fim, and is held in suspension by an air current. The amount of talcum powder is supplied at 2 kg per cubic metre size of the test chamber. The enclosure under lest is placed inside the chamber and is connected to a vacuum pump which maintains, inside the enclosure, a differential pressure equivalent to not more than a 200 mm eolumn of water. 

Anechoic A room that has a low degree of acoustic reverberation, such as an anechoic test chamber. 

Urtiew (1981) performed experiments in an open test chamber 30 cm high x 15 cm wide x 90 cm long. Obstacles of several heights were introduced into the test chamber. Possibly because there was top venting, maximum flame speeds were only on the order of 20 m/s for propane-air mixtures. 

TEST CHAMBERS FOR HIGH-ALTITUDE RESEARCH STUDY... 

Fig. 6.—Large magnet with test chamber enclosing pole pieces and dumbbell assembly windowed cover and gasket have been removed from test chamber.

The gas to be tested may be drawn or forced at the rate of a few cubic centimeters per minute through the test chamber, which in present models has a volume of about 4 ml., or it may be introduced after evacuating the test chamber. The instrument indicates correctly the magnetic susceptibility of the gas in the test chamber within a few seconds the main delay in reading the instrument is caused by the time required to introduce the gas. 

The tests generally involve some form of maze but the simplest is the passive avoidance test. In this the animal learns that in a certain environment it will be punished with an electric shock for some particular action, like stepping onto a special part of the floor of the test chamber. The test of memory is how long the rat avoids (remains passive to) making the movement that will initiate the shock. Of course, drugs that reduce the animal s anxiety also modify the response. Using a maze in its simplest T shape, the animal is placed at the base of the vertical arm and a food reward at the end of one of the horizontal arms. Clearly the animal has to learn which arm contains the reward. Memory is assessed by the time taken for a food-deprived animal to reach the reward and the number of false arm entries. This simple system can be made more complex by introducing many more arms and branches but the principle is the same. 

Figure 1. Ideal fluidization curve, showing typical test chamber and relevant parameters Ah, Ap, l and Vmf.

Center of the U.S. Bureau of Mines. The radon chamber in Denver Research Center is designed to provide adjustable humidities and a well controlled, monitored radon and CN concentration. It has a length of 213 cm, a diameter of 152 cm, and a volume of about 3.89 m. The walls are made of 0.5-cm rolled steel with welded seams. Figure 1 shows the general scheme of the test chamber excluding the transducers and data aquisition system. 

Rn-222 is produced from a dry Ra-226 source with an activity of about 2 mCi housed in a lead shield. Radon is carried from the source by means of compressed air with a regulated flow rate of 200 cnr/min. The test chamber is operated with a 75 1/min air pump located downstream (Figure 1XDroullard, et al., 1984) that exhausts to the outside of the building. The flow rate of this air pump is monitored by a mass flow transducer whose signals are converted to volumetric flow rates. 

It has been found that the activity which is conventionally referred to as the "unattached" fraction is actually an ultrafine particle aerosol with a size range of 0.5 to 3 nm. The hydroxyl radical from water molecule radiolysis is a key element to the particle formation mechanism. By injecting different concentrations of S02 into the test chamber, a possible particle formation mechanism has been suggested as follows Oxidizable species such as S02 reacts promptly with hydroxyl radicals and form a condensed phase. These molecules coagulate and become ultrafine particles. 

M. van Bommel, B. van Elst, F. Broekens, Emission of organic acids from wooden construction materials in a small test chamber preliminary results of optimisation of the solid phase micro extraction technique, 4th Meeting of the Indoor Air Pollution Working Group, Copenhagen, 2001. 

Figure 12.9-6. A small prototype unit (a) consists of a fan and coated monolith was placed in a test chamber shown in (b) and tested for VOC removal at ambient conditions, (c) The results show that the VOC level was decreased by half in less than an hour.

The test results in Fig. 12.9-10 show a clear and immediate reduction in airborne bacteria when the Prototype Unit was turned on. Ninety percent reduction of B. subtilis, P. aeruginosa and S. epidermidis were reached at 1.5, 10 and 3 minutes of Prototype operation, respectively. The control experiments showed fluctuations due to poor circulation within the test chamber, but otherwise maintained a bacteria level higher than when the Prototype Unit was in operation. 

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