Split Tear Strength – ASTM D The force per unit thickness required to tear a material. Test specimens are placed in a tensile test machine. The jaws are set. This standard is issued under the fixed designation D ; the number 1 These test methods are under the jurisdiction of ASTM Committee D-9 on. Electrical. ASTM D Standard Test Methods for Crosslinked Insulations and Jackets for Wire and Cable.
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ASTM D — ASTM D von A number in parentheses indicates the year of last reapproval. A superscript epsilon e indicates an editorial change since d4470 last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense. To determine the test to be made on the particular insulation or jacket, refer to the product speci?
These test methods do not apply to the class asm products known as? It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Therefore, tests are done on insulated or jacketed wire or cable in these test methods solely to determine the relevant property of the insulation or jacket and not to test the conductor or completed cable.
ASTM D470 – 13
Current edition approved September 1, Originally approved in Last previous edition approved in as D — BoxSouth Yarmouth, Aetm E470 exposure limits are set by governmental agencies and are usually ast upon recommendations made by the American Conference of Governmental Industrial Hygienists. Mercury, being a liquid with high surface tension and quite heavy, will disperse into small droplets and seep into cracks and crevices in the?
This increased area of exposure adds signi? The use of a commercially available emergency spill kit is recommended whenever a spill occurs.
Mercury vapor concentration is easily monitored using commercially available sniffers. Make spot checks periodically around operations where mercury is exposed to the atmosphere. Make thorough checks after spills. It is essential that the test apparatus, and all associated equipment that may be asstm connected to it, be properly designed and installed for safe operation.
Solidly ground all electrically aztm parts that any person might come in contact with during the test. Provide means for use at the completion of any test to ground any parts which: Thoroughly instruct all operators in the proper way to conduct tests safely. When making high voltage tests, particularly in compressed gas or in oil, the energy released at breakdown may be suff?
Design test equipment, test chambers, and test specimens so as to minimize the possibility of such occurrences and to eliminate the c470 of personal injury. See Sections 20, 27, 33, 42, 48, 54, 62, 68, 76,and Because d740 this it is important to measure the concentration of ozone in the axtm, using commercially available monitoring devices, whenever the odor of ozone is persistently present or when ozone generating conditions continue.
Use appropriate means, such as exhaust vents, to reduce ozone concentrations to acceptable levels in working areas. The physical test values give an approximation of how the insulation asmt physically perform in its service life. Physical tests provide useful data for research and development, engineering design, quality control, and acceptance or rejection under speci?
No sample shall be r470 from lots of less than ft. Tensile strength, tensile stress, and ultimate elongation Permanent d4770 For Aging Tests: Air pressure, heat, or oxygen pressure Air oven For Oil Immersion 3 d4470 3 3 3 One specimen of each three shall be tested and the other two specimens held in reserve, except that when only one sample is selected all three specimens shall be tested and the average of the results reported.
For the tear axtm, six individual specimens as described in 8. When the full cross section is used, the specimens shall not be cut longitudinally. In the case of wire and cable of AWG 6 and larger, or in the case of wire and cable smaller than AWG 6 having an insulation thickness greater than 0.
In extreme cases, use of a segmental specimen is permitted. Specimens for tests on jackets shall be taken from the completed wire or cable and cut parallel to the axis of the wire or cable. With the exception of the tear tests, the test specimen shall be either a segment or sector cut with a suitable sharp instrument or a shaped specimen cut out with a die and shall have a cross-sectional area not greater than 0.
Remove surface irregularities, such as corrugations due to stranding, etc. In most cases a test specimen which is an entire section is obtained, free from surface incisions and imperfections.
Introduce the mercury at one end of the specimen between the insulation and the tinned surface of the conductor, with the specimen inclined on a support with the end to which the mercury is applied at the top. The separation of the insulation results from the amalgamation of the tin of the conductor with the mercury. The amalgamation is assisted by? It is also possible to facilitate the removal of the insulation by stretching the conductor to the breaking point in a tensile-strength machine.
Care should be exercised to keep mercury from the hands.
The use of rubber gloves is recommended for handling specimens as in 8. Make an effort to separate the jacket from the insulation by slitting the covering through to the conductor and pulling the jacket and insulation apart by pliers. Immersing r470 sample in hot water for a few minutes just prior to pulling off the jacket often facilitates this procedure.
If the jacket cannot be removed, prepare specimens by buffing. Equip the buffing apparatus with a cylindrical table arranged so that it can be advanced very asm.
Remove the conductor from two short lengths of wire by slitting the covering. D70 one length of covering into the clamps of the buffing apparatus so that it lies?
The jacket is buffed off, with due care not to aatm any further than necessary, or overheat the material. Repeat the process with the other length of covering, except that the insulation is buffed off. Die-cut specimens shall be prepared from the buffed pieces after they have been allowed to recover for at least 30 min.
Jackets with a thickness of less than 0. After irregularities, corrugations, and reinforcing cords or wires have been removed, the test specimen shall conform to the dimensions shown in Fig. The thickness of the test specimen shall be not greater than 0. Split the specimen longitudinally with a new razor blade to a point c470.
Perform tests between 24 h and 60 days after crosslinking unless agreed to by the manufacturer. Do not heat, immerse in water, or subject the specimens to any mechanical or chemical treatment not speci? Age specimens having cable tape applied prior d47 crosslinking with such tape removed.
Measurement of Thickness of Specimens 9. The micrometer and microscope shall be capable of making measurements accurate to at least 0. Take the minimum thickness of the insulation as the difference between a measurement made over the conductor or any separator plus the thinnest insulation wall, and the FIG.
Do not include the thickness of any separator in the thickness of insulation. Take the average of these determinations as the average thickness of the jacket.
Take the average of these determinations as the average thickness. When the lot consists of more than two coils or reels and less than 20 coils or reels, make at least one determination of the thickness on each of two coils or reels taken at random.
ASTM D – 13 Standard Test Methods for Crosslinked Insulations and Jackets for Wire and Cable
Calculation asmt Area of Specimens Calculate the area of a stranded conductor from its maximum diameter. The height of the segment is the thickness of insulation on the side from which the slice is taken. If necessary, obtain the values from a table giving the areas of segments of a unit circle for the ratio of the height of the segment to the diameter of the circle.
This applies either to a straight test specimen or to one stamped out with a die, and assumes that corrugations have been removed.
Physical Test Procedures For the set test mark the specimens with gage marks 2 in. Place the specimen in the jaws of the testing machine with a maximum distance between jaws of 4 in. Release the test specimen within 5 s, and determine the distance between bench marks 1 min after the beginning of release. The set is the difference between this length and the original 2-in. Place the two halves of the split end of the test specimen in the jaws of the tension testing machine and separate the jaws at the rate of 20 in.
Determine the tear resistance by dividing the load in pounds or kilograms required to tear the section by the thickness of the test specimen in inches or millimeters. Consider the average of the results obtained on all test specimens as the value of the tear resistance. Aging Test Procedures Perform physical tests on both aged and unaged specimens at the same time. Oil Immersion Test At the end of the 18 h remove the specimens from the oil and allow to rest at room temperature for a period of 4 6 1?
Determine the tensile strength and elongation at the same time that the original properties are determined see Section Likewise, the elongation is based on the original distance between the gage marks applied to the specimen before immersion in the oil. Failure of either of the retests indicates nonconformity of the sample to the requirement speci?
Precision and Bias No activity has been planned to develop such information. The electrical test values give an indication as to how the insulation will perform under conditions similar to those observed in the tests. Electrical tests provide useful data for research and development, engineering design, quality control, and acceptance or rejection under speci?
Types of Voltage Tests The partial discharge, ac voltage, insulation resistance, and dc voltage tests are performed on entire lengths of completed cable. Order of Testing The sequence of other testing is not speci?