ASTM D669-03 pdf free.Standard Test Method for Dissipation Factor and Permittivity Parallel with Laminations of Laminated Sheet and Plate Materials.
Examine the mounted strips to determine smoothnessand freedom from irregularities. Make certain that all burrshave been removed from the cut edges. Sand, mill or lathe-cutthe exposed cut surfaces if necessary, taking care that the resincontent or other characteristics of the material are not affected.
Condition the mounted strips for 48 h at 50 3°c.Allow to cool in a desiccator for at least 1 h, or suflficient timeto bring the assembly to room temperature. Other conditioningprocedures may be employed as agreed upon between all theparties concerned.
Apply the foil electrodes to each side of the testspecimen using a thin film of petrolatum as an adhesive,making certain that the electrodes are centered on the specimenand with respect to each other. Eliminate any air gaps under thefoil by smoothing the electrode and pressing with a suitableroller or soft cloth.
ASTM D669 pdf download.Lethal voltages may be present during thistest. lt is essential that the test apparatus and all associatedequipment that may be electrically connected to it be properlydesigned and installed for safe operation.Solidly ground allmetal parts that any person might come into contact withduring the test. Thoroughly instruct all operators in the properway to conduct the test safely. When making high voltage tests,particularly in compressed gas or in oil, the energy released atbreakdown may be sufficient to result in fire，explosion，orrupture of the test chamber. Design of test equipment，testchambers and test specimens should be such as to minimize thepossibility of such occurrences, and to eliminate the possibilityof personal injury.Measure the ac capacitance and dissipation factor of thetest specimens cut in the lengthwise and crosswise directions,at a specified frequency and temperature using the proceduresdescribed in Test Methods D 150. Record the applied voltage,the effective voltage gradient and the diameter of the electrodesused. Calculate the loss index and permittivity.
For accuracy in the calculation of permittivity, where thesurfaces have not been sanded，milled,or lathe-turned afterassembly in the frame, measure the thickness of the individualstrips in a direction parallel with the laminations and averagethese to obtain the specimen thickness.ASTM D669 pdf download.