Testing methods dripping test

Standard test method for measuring MEK resistance of ethyl silicate (inorganic) zinc-rich primers by solvent rub, ASTM Standard ASTM D4752-10, ASTM International, West Conshohocken, PA, 2010. Standard practice for determining the waterfastness of images produced by ink jet printers utilizing four different test methods - drip, spray, submersion and rub, ASTM F2292-03, ASTM International, West Conshohocken, PA, 2008. Book of Standards Volume 15.09. 

Regulatory Legislation. In Febmary 1978, the Consumer Products Safety Commission approved changes in the FF-3 and FF-5 standards for children s sleepwear. It eliminated the melt—drip time limit and coverage for sizes below 1 and revised the method of testing the trim. This permits the use of untreated 100% nylon and 100% polyester for children s sleepwear (157—162). 

Resistance to the Solvent Action of Fuels. Sulfur—asphalt concretes were less affected by the solvent action of fuels than was normal asphaltic concrete. The solvent action of three fuels—gasoline, JP-4 jet fuel, and No. 2 diesel fuel—was tested on samples of normal asphaltic concrete and on 15-, 25-, and 35-vol % sulfur-asphalt concretes. Two test methods developed by McBee (15) were used to determine loss in weight and loss of stability on drip and total immersion testing of Marshall compaction samples. 

This test has been criticized because it does not simulate actual building fire conditions [5,6], An additional problem with foamed samples is that the specimens either retract out of the reach of the flame or drip on to the floor of the tunnel. In Canada this has been addressed by using a downward-facing burner and mounting the specimens on the floor of the tunnel. Despite its limitations, the Steiner Tunnel method continues to be used to test and rate thermoplastic foams. 

Both these fractionation methods permit the contents of the centrifuge tube to drip sequentially into a set of test tubes. Ideally it would be desirable for each test tube or fraction to receive the same volume of solution. Unfortunately this is often not the case. Droplets obtained from the least dense region of the gradient are also the least viscous, and therefore exhibit a smaller amount of surface tension than do droplets obtained from denser regions. Since the size a droplet can attain before falling away from the tube is a function of its surface tension, the drops obtained from the top of the gradient are smaller than those obtained from the bottom. If quantitation of the gradient contents is desired, this problem must be eliminated or appropriate corrections made for it. 

German and other European physicians also latched on to combination therapy of Proleukin with Interferon-alpha as helpful to outpatient or home care.35 A series of reports in German medical journals suggested that subcutaneous infusion and combination therapy would result in fewer side effects, less strain on patients, and more successful treatment of cancer.36 The approach drew sufficient interest from physicians that the company sponsored tests to document its efficacy and eventually presented data to the BGA supporting this method of application. Cetus used a database of 425 patients to compare 225 patients who received Proleukin as an intravenous drip infusion with 200 patients who injected themselves with Proleukin combined with Interferon-alpha. The two approaches did not result in statistically different outcomes in terms of cancer remission, but were strikingly different in their toxicity. Intravenous application had a remission rate of 15 percent, while 30 percent of the patients suffered from severe toxicity. In contrast, the subcutaneous application had a 20 percent remission rate with only 5 percent of patients experiencing severe toxicity.37... 

This acetone which remains still contains a lot of PETN. The best way to get the PETN out of the acetone which remains is to drip 190 proof grain alcohol (vodka) or 91% isopropyl alcohol into the acetone with stirring. As alcohol is added to acetone, its ability to dissolve PETN decreases. This is because PETN doesn t dissolve well in alcohol, so adding it to the acetone makes the solution lousy at dissolving PETN. This method is much better than boiling away more acetone because that method leads to a final crop of crystals that are dirty. When the solution is about half alcohol, all the PETN should be out of solution in the form of crystals. This is filtered out, and the acetone-alcohol mix is then tested to see if all the PETN is out of it by adding some more alcohol to see if more crystals form. If they do, alcohol is added until no more crystals form. 

The particle method is carried out as follows. Several particles of Chromosorb W AW (acid washed a commercially available support for the liquid phase in gas chromatography) were placed on a watch glass, and 5 pi of a diethyl ether or ethyl acetate solution of the test compound, adjusted to an appropriate concentration, was dripped carefully on to these particles. Any excess solution on the watch glass was immediately absorbed with a piece of filter paper, and the particles were then air-dried at room temperature. A few of the treated particles were then dropped into an aqueous suspension of zoospores in a small Petri dish (see above). The behaviour of zoospores around the particles was observed microscopically after a period of 1 min. Control particles were treated with ether or ethyl acetate only. 

A method was described by Burton et al. (1981) involving the direct application of irritant test substance to the cornea of eyes removed immediately after sacrifice of rabbits and subsequent evaluation of the cornea for swelling, opacity, and fluorescein staining, The eye is mounted on a clamp in a temperature-controlled superfusion chamber with isotonic saline dripped onto the surface of the cornea, After an equilibrium period of 30-45 min, the test material is applied to the surface of the cornea and then washed off. Eyes are inspected macroscopically. Then, with a slit-lamp biomicroscope, the comeal thickness is measured and any fluorescein staining noted. The predictive value of the method has been confirmed in several studies (Commission of the European Communities, 1991 Koeter and Prinsen, 1985 Price and Andrews, 1985 Whittle et al., 1992), By using comeal thickness measurement, fluorescein retention, and comeal opacity as criteria for ocular injury, the suitability of the chicken eye as an enucleated model was confirmed by Prinsen and Kocier (1993) and Prinsen (1996). 

The test method of ASTM D 3801-1980 is also practically identical to the Vertical Burning Test for Classifying Materials 94V-0, 94V-f or 94V-2 but only the combustion times and the observation of dripping are recorded without any flammability rating of the material. 

A similar test method is described in ASTM D 3638-77. Test specimen disks of 50 or 100 mm dia. and at least 25 mm in thickness are dripped onto by a 0.1 % NH4CI solution. The CTI is determined by plotting the number of drops at breakdown against voltage and then reading the voltage at 50 drops. 

Less efforts have been devoted to the problems of dripping. This phenomenon is normally observed in the test procedures of flammability (cf. Section 3) and some specific methods will be reviewed in Section 4.3. 

For testing combustion dripping, a French standard, NF P 92-505-1985, describes a method which is independent of any test procedures for other properties. 

Four different test methods are outlined to simulate the most common ways that materials are exposed to water drip, spray, submersion and a rub method. Actually, the method of water application may greatly affect the outcome of the test. While one or more of the test methods may be performed, to best qualify a product aU four test methods described in the standard should be used. The drip and spray test are evaluated visually, while the submersion and rub tests can be evaluated visually and instrumentally. 

Unless otherwise agreed upon, the samples are placed at a 15-30 angle from vertical. (Automotive components, however, are often tested in in-car position.) This orientation allows the condensation to run down the specimens and minimize condensation pooling. Overcrowding should be avoided. An important aspect of the test is utilization of a free-falhng mist, which uniformly setdes on the test samples. Samples should be placed in the chamber so that condensation does not drip from one to another. Test durations are typically in 24-h increments and can range from 24-5000 h. (Where salt fog exposure is a part of a more complex test method, exposure time can be as little as 15 min.) Except for sample rotation and daily monitoring of collection rates, the cabinet should remain closed for the duration of the test. 

Jaske and Castillo [36] used RR Moore rotating beam fatigue machines to study several roll materials with simulated white water solutions dripped onto the test specimen surface. Castillo et al. [19] used rotating bending tests to evaluate the corrosion fatigue resistance of duplex stainless steel suction roll alloys. Yoshitake et al. [21] also used this method. 

In a new approach, zeta potential measurements were carried out on drip-coated microscope slides using a SurPASS electrokinetic analyzer and clamping cell (Anton PAAR). Each run consisted of a forward and backward pumping cycle taking 15 minutes. Three runs ( 45 minutes) provided a much more demanding test of stability in dilute polyelectrolyte (10 M KBr) compared to the capillary method used previously ( 2 minutes) [108]. Zeta potentials for polymer coatings are known to be affected by pH [113] initial measurements reported here were carried out at pH 7. 

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