Test specimens, conditioning procedure

The ASTM test describes in detail the apparatus for measuring compressive properties, preparation of test specimens, conditioning, and procedures. The standard test specimen is recommended to be in the form of a right cylinder or prism whose length... 

ISO R489 suggests two methods based on Abbe refractometer and the Becke line methods. It does not recommend any specimen conditioning procedure prior to the test. DIN 53491 provides practical details relevant to refractometer measurements. It recommends test temperature... 

Effectiveness of these EP oils can be evaluated by a number of laboratory test units such as those shown in Figure 4. While the American Society for Testing and Materials (ASTM) procedures describe a number of standard test procedures (10), the operating conditions and test specimen materials should be chosen to simulate as nearly as possible those in an appHcation. 

Laboratory tests used in the development of inhibitors can be of various types and are often associated with a particular laboratory. Thus, in one case simple test specimens, either alone or as bimetallic couples, are immersed in inhibited solutions in a relatively simple apparatus, as illustrated in Fig. 19.34. Sometimes the test may involve heat transfer, and a simple test arrangement is shown in Fig. 19.35. Tests of these types have been described in the literatureHowever, national standards also exist for this type of test approach. BSl and ASTM documents describe laboratory test procedures and in some cases provide recommended pass or fail criteria (BS 5117 Part 2 Section 2.2 1985 BS 6580 1985 ASTM 01384 1987). Laboratory testing may involve a recirculating rig test in which the intention is to assess the performance of an inhibited coolant in the simulated flow conditions of an engine cooling system. Although test procedures have been developed (BS 5177 Part 2 Section 2.3 1985 ASTM 02570 1985), problems of reproducibility and repeatability exist, and it is difficult to quote numerical pass or fail criteria. 

Conditioning procedures of test specimens and products are important in order to obtain reliable, comparable, and repeatable data within the same or different testing laboratories. Procedures are described in various specifications or standards such as having a standard laboratory atmosphere [50 2% relative humidity, 73.4 1.8°F (23 1°C)] with adequate air circulation around all specimens. The reason for this type or other conditioning is due to the fact the temperature and moisture content of plastics can affect different properties. 

As reviewed it is important that test specimens or products be properly prepared based on available specifications and/or standards that provide controlled conditioning procedures when conducting weathering as well as all other tests. The following is one example. There are other conditions set forth to provide for testing at higher or lower levels of temperature and humidity. 

The conditions under which the material is tested are crucial. The top of the exposure chamber must be sealed and the tank should contain no free air space. A stirring mechanism in the tank keeps the leachate mixture homogeneous and a heater block keeps it at an elevated temperature as required for the test. Stress conditions of the material in the field should also be simulated as closely as possible. The original U.S. EPA Method 9090 test included a rack to hold specimens under stress conditions but was revised when some materials shrank in the leachate. Due to the hazardous nature of the material, testing should be performed in a contained environment and safety procedures should be rigorously followed. 

Conditioning procedures for specimens after curing and prior to testing. 

Blends were produced in a small Banbury mixer. About 3 lb of dry-blended material was added to the Banbury. After the flux point, blends were run for two more minutes and dumped. Conditions were speed No. 2, 30 psi on the ram, and a dump temperature of 310°F. Test specimens were molded on a 3-oz Van Dorn injection-molding machine front, middle, and rear zones were 500, 485, and 470°F, respectively. The mold temperature was 160°F the molding cycle was typical for ABS. Test methods were ASTM Standard Procedures. 

Leather is a natural product and is subject to extensive variability. The physical and chemical properties vary considerably depending on the location from which the leather test sample is taken. The standard test method from the American Society for Testing and Materials (ASTM D2813, 1997) ensures random sampling of finished leather and fabricated leather items for physical and chemical tests. Test specimens should be cut from only one side of the backbone with their long dimension perpendicular to the backbone line. Test specimens should be taken from different parts of the shoulder, belly and tail of the leather. The number of specimens taken depends on the reliability of the test results, the deviation and the error of the testing procedures and should be recorded on the test report. Physical tests of leather and leather products, unless otherwise specified, should be performed under the standard atmospheric conditions of 50 4% relative humidity at 23 1 °C. 

The test procedures are intended primarily for use by the purchaser or user. The noduct manufacturers voluntarily certify that their products meet the appropriate ASTM specifications. To do this, they must run sufficient tests by these procedures to determine that their products conform to the specifications. All of the tests require that specimens be conditioned for an extended period of time before testing, so the tests cannot be used for direct process control. It is desirable that the tests measure significant properties of the products so that they can be used for product evaluation. 

Four 2-hour dessicator test specimens, each measuring 7 cm x 12.7 cm (2-3/4 in. X 5 in.), were cut from each strip and conditioned overnight. Two desiccator tests were conducted for each product type, with each desiccator containing eight specimens. Tests were performed in accordance with standard procedure FTM 1 (16). 

In addition to testing methods and product specifications, ASTM Committee D-20 on Plastics has also prepared definitions of terms and recommended practices for molding test specimens and constructing testing equipment, conditioning and weathering procedures, and related standards. These are published in the ASTM books of standards (4-7). There is also a federal standard for laboratory atmospheric conditions for testing (34). 

The procedure specifies a testing machine, loading noses and supports (see Fig. 7.4), micrometers for measuring the width and depth of the test specimen, and conditioning of the test specimens. At least five specimens for each sample should be tested according to the procedure. It should be pointed that according to AC 174, flexural testing of minimum 15 specimens is recommended. 

The ASTM methods recommend test specimens of 12 by 12 or 6 by 6 in. in size. After conditioning as described in the procedure, the specimen shall be weighed and the width, length, and thickness measured. The specimen shall be submerged horizontally or vertically under 1 in. of distilled water at 20°C (68°F). After 24 h of submersion (Method B) the specimen shall be suspended for 10 min to drain, then remaining water wiped off, the specimen weighed, and the thickness measured. The procedure notes that specimens placed in water vertically will absorb considerably more water then those placed horizontally. 

A specimen may be in the form of pellets, powder, sheet, film, plastic cellular, or composite materials, with a specimen weight of 3.0 0.2 g. The ASTM procedure describes in detail cutting or folding sheet or film materials and conditioning test specimens. 

This practice covers specific procedures and test conditions for fluorescent UV exposure of plastics, including the preparation of test specimens and the evaluation of test results. The procedures are intended to induce property changes in the plastics... 

The second set of conditions is related to this sampling operation and the test specimens derived from the samples. The sampling procedure should... 

In the first step of the test procedure, the flammability of a red oak specimen is measured. With a correct adjustment of the experimental conditions (gas flame, air supply), the flame reaches the end-point of the wood specimen in 5.5 min. The thermocouple reading and the photoelectric cell output at the vent end are recorded every 15 s and the curves of the flame spread distance and the smoke density are plotted against time. In the second step, the same procedure is followed using an asbestos cement board then, in the third step, using the test specimen. 

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