ASTM D149-97A PDF
Buy ASTM Da() Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at. Dielectric Strength ASTM D, IEC Scope: Dielectric Strength is a measure of the electrical strength of a material as an insulator. Dielectric strength is. ASTM DA – Designation: D – 97a (Reapproved ) An American National Standard Standa.
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ASTM D 97a 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. Molecular Structure and Electrical Behavior, Vol.
Dielectric Strength ASTM D149, IEC 60243
Except in cases where the effect of exposure on dielectric strength is being investigated, it is customary to control or limit the relative humidity effects by standard conditioning procedures.
Some of these effects can be incorporated in laboratory tests, and a better d149-9a of the material will result, adtm the nal consideration must always be that of the performance of the material in actual service.
Also see Note 1. When making a direct comparison of results from two or more laboratories, evaluate the precision between the laboratories. In these uses of the test it is the relative value of the breakdown voltage that is important rather than the absolute value. Accurately determine the voltage at breakdown.
Send us a request Wilton UK: Through our network of over 43, people in 1, laboratories and offices in countries, Intertek provides quality and safety solutions to a wide range of industries around the world. This type of failure, usually associated with slow-rise tests at elevated temperatures, will in some cases d1149-97a reversible, that is, it is possible that recovery of the dielectric strength will occur if the specimen is allowed to cool to its zstm test temperature before reapplying voltage.
This phenomenon is most commonly evidenced during the test by an abrupt visible and audible rupture through the thickness of the specimen, resulting in a visible puncture and decomposition of the specimen in asym breakdown asstm. It is essential that the test apparatus, and all associated equipment that may be electrically connected to it, be properly designed and installed for safe operation.
This study made use of one electrode system and one test medium. If tests are to be made at other than room temperature, the bath must be provided with a means for heating or cooling the liquid, and with a means to ensure uniform temperature. D Refer to the appropriate standard for the load force applied by the upper electrode assembly. Weak spots within the volume under asm sometimes determine the test results.
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. Small baths can in some cases be placed in an oven see 6. Results may be affected also by the material from which the electrodes are constructed, since the thermal and discharge mechanism may be inuenced by the thermal conductivity and the work function, respectively, of the electrode material.
Standards which refer to this method should determine for the material with which that standard is concerned the applicability of this precision statement to that particular material.
In these uses of the test it is the relative value of the breakdown voltage that is important rather than the absolute value. Avoid the outer few layers of roll material, the top sheets of a package of sheets, or material immediately next to an edge of a sheet or roll, unless the presence or proximity of defects or discontinuities is of interest in the investigation of the material.
Each of these three methods has the same basic set-up, which consists of the test specimen placed between two electrodes in air or oil. If failure occurred while the voltage was being increased to the starting voltage the failure time shall be zero. It may also be asgm to determine dielectric breakdown voltage along the interface between a solid specimen and a gaseous or liquid surrounding medium ash1 This test method is under the jurisdiction of ASTM Committee D09 on 1d49-97a and Electronic Insulating Materials and is the direct responsibility of Subcommittee D If the time to breakdown cannot be adhered to, the time shall be made a part of the report.
D — 09 Preferred starting voltages, Vs are 0. Unless the breakdown path between the electrodes is solely within the solid, results in one medium cannot be compared with those in a different medium.
Last previous edition approved in as D — 97a In this case, the times to failures shall be made a part of the report. In most cases, tests using Type 7 electrodes are made with the plane of the electrode surfaces in a vertical position. G It is acceptable to use other diameters, provided that all parts of the test specimen are at least 15 mm inside the edges of the electrodes.
In many cases the dielectric strength of a material will be the determining factor in the design of the apparatus in which it is to be used. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard. In most cases, tests using Type 7 electrodes are made with the plane of the electrode surfaces in a vertical position.
The transformer, its voltage source, and the associated controls shall have the following capabilities: Discharges may occur in any internal voids or bubbles that are present or may develop. Ordinarily the rate is selected to approximate the average rate for a step-by-step test. Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm.
First, the condition of a material as installed in apparatus is much different from its condition in this test, particularly with regard to the con? Originally approved in Test results are also affected by the electrode geometry. Precision and Bias Other electrodes may be used as specied in ASTM standards or as agreed upon between seller and purchaser where none of these electrodes in the table is suitable for 1d49-97a evaluation of the material being tested.
Dielectric Strength ASTM D, IEC
Design test equipment, test chambers, and test specimens so as to minimize the possibility of such occurrences and to eliminate the possibility of personal injury.
Validating the specifications, value and safety of your raw materials, products and assets. Calibrate the current-sensing dial in terms of specimen current. Such repeated applications of voltage may be used to give positive evidence of breakdown and to make the breakdown path more visible.