ASTM D Standard Test Method for Dissipation Factor (or Power Factor) and Relative Permittivity (Dielectric Constant) of Electrical Insulating Liquids. Find the most up-to-date version of ASTM D at Engineering We perform testing by ASTM D on electrical insulating liquids used in cables, transformers, oil circuit breakers, and other electrical apparatus.

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For the first use, a low value of relative permittivity is often desirable in order to have the capacitance aatm as small as possible, consistent with acceptable chemical and heat transfer properties. Dissipation factor or power factor may be useful as a means of quality control, and as an indication of changes in quality resulting from contamination and deterioration in service or as a result of handling.

Specific warnings are given in The reported value of D or PF may be expressed as a decimal value or as a percentage. If the difference in the measurements of the two test specimens is equal to or astj than 0.

Insulating oil dielectric loss and resistivity tester is used for measuring dielectric dissipation factor and DC resistivity of insulating oil and other insulating liquids.

Replace the beaker with the remainder of the heated sample on the hot plate. Accordingly, there is no simple conversion factor for deter- mining the dissipation factor at 60 Hz, for example, if the measurements are made at either a higher or lower frequency.

In general, since the dissipation factor or power factor of insulating oils in good condition have decimal values below 0. Contact Now Customized Request. Due regard should be given to the precautions outlined in Section Large-screen LCD,backlight, display is clear.


ASTM D液体绝缘材料介质损耗测试法_百度文库

However, an intermediate value of relative permittivity may sometimes be advantageous in achieving a better voltage distribution of a-c electric elds between the liquid and solid insulating materials with which the liquid may be in series. In some research investigations, tests may be made at considerably higher temperatures while in other cases, particularly for tests on cable oils in service, tests may be made over a range d9924 temperatures. We have a strong team including top sales, skilled engineers and we have our own manufacture with high quality.

Use a shielded wire or coaxial cable for connecting the guard and measuring electrodes to the bridge. Consult such procedures before samples are taken. Plated surfaces that may be satisfactory for testing liquids having low acidity and for short periods of time are gold, platinum, nickel, chromium over nickel, or rhodium. Not exactly what you want?

Wooden Box with Foam Inside. Immediately return the lled cell d294 the test chamber adjusted to a temperature above the desired test temperature and make the necessary electrical connections to the cell. Link to Active This link will always route to the current Active version of the standard.

Find Similar Products By Category. Wooden box with foam inside, 3. Precision and Bias Oil cup is cleaned automatically and has electrode calibration function.

Please see the below display and the operation details: A number in parentheses indicates the axtm of last reapproval. However, an intermediate value of relative permittivity may sometimes be advantageous in achieving a better voltage distribution of ac electric fields between the liquid and solid insulating materials with which the liquid may be in series.

This standard is subject to revision at any time by the responsible technical committee and must be reviewed every ve years and if not revised, either reapproved or withdrawn. As a precaution against this eventuality, use a suitable stopper to plug this opening prior to starting the cleaning operation. Tests at higher stresses are desirable but shall not 9d24 such values that electrical discharges across the cell insulating surfaces occur or that internal ionization of the specimen may be expected.


ASTM D924 Large-Screen Auto Washing Insulating Oil Dielectric Loss Tester

It is essential, therefore, that the procedures outlined below be closely followed. The alignment of the electrodes shall not be inuenced by this temperature nor by the operation of lling the cell with the test liquid. Historical Version s – view previous versions of standard Translated Version s: Last previous edition approved in as D — For optimum procedure do not exceed 20 min for this time.

Where this applies, it is imperative that each laboratory evolves a good cleaning procedure for the cell used so that repeatable results can be obtained.

The dissipation factor of these insulating materials must necessarily be low, particularly that between the guard and measuring electrodes; otherwise difficulty may be experienced in balancing the guard circuits at elevated temperatures.

Measured temperature and system clock. Leakage across these paths has been found to produce an unsteady bridge balance on some bridges. On some instruments the cell must be in place before lling with specimen. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters.

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