The ASTM D257 test standard describes direct current (DC) procedures for determining the DC insulation resistance, volume resistance, volume resistivity, surface resistance, and surface resistivity of electrical insulating materials. The resistance/conductance of a material specimen or capacitor is calculated by measuring the current or voltage drop under specific experimental conditions. The IEC 62631-3-1 standard is also utilised to measure the surface and volume resistivity of materials. Surface and volume resistance or conductance can be measured individually with the proper electrode setups. The resistance/conductivity of a material sample can be determined given the dimensions of the specimen and electrode are known. The ASTM D257 test method is generally applicable to insulating materials, although it is not appropriate for electrical resistance and conductance of moderately conductive materials.
Read More
GET STARTED
ASTM D257 Introduction
ASTM D257 is a test method designed to measure the conductance, conductivity, volume, and surface resistivity of electrical insulating materials. The mechanical, chemical, and heat-resistant properties of the specimen are determined through this method. Resistivity is a key aspect of high-voltage insulation, antistatic packaging, and microelectronic components. Industries are assured of the quality of products, consistency, and conformity to standards through these standardised test processes. The results obtained are specially used for quality control and specification purposes. The procedure involves applying a direct voltage to a material specimen and measuring the current that passes through it. This measurement enables the calculation of both volume and surface resistivity, which are crucial for determining a material’s effectiveness as an electrical insulator. ASTM D257 is applicable across various industries, including electronics and aerospace, where ensuring reliable insulation is crucial for both quality control and material qualification. In essence, this standard is a fundamental tool for verifying that insulating materials meet stringent standards.
ASTM D257 test method is generally applicable to insulating materials, but not suitable for use in measuring the electrical resistance and conductance of moderately conductive materials. The method also provides information about the voltage stress limits, electrode geometry, precision of specimen configuration, and finite electrification.
Service Name
Remarks
ASTM D257 Testing
Contact US
Get Certified ASTM D257 / IEC 62631-3-1 for High-Precision Electrical Insulation Evaluation
ASTM D257 and IEC 62631-3-1 certifications are used to guarantee that testing laboratories use internationally accepted methods of resistivity testing. Compliance indicates the technical proficiency of dealing with delicate electrical measurements and ensures that the results are consistent, reproducible, and traceable. Certified companies are assured of the reliability of the materials, enhanced product safety, reduced risk of electrical leakages, and customer and regulatory needs. The certification improves quality assurance, advances the R&D work, and improves the reputation of the electrical material tests.
ASTM D257
ASTM D257 / IEC 62631-3-1 Testing Procedure and Requirements
Insulation Resistance or conductance
The specimen is placed in the test chamber, and measurements of conductivity and resistivity are made using a device with the required sensitivity and accuracy. The time for electrification is specified as 60 seconds, and a voltage of 500 V is applied.
Surface resistance or conductance
The dimensions and distance between the electrodes are determined along with the surface resistance and conductance between electrodes. The time for electrification is specified as 60 seconds, and the direct voltage of 500 V is applied.
Volume Resistivity
Measured through specimen thickness using guarded electrodes to isolate leakage currents.
Calculations
Resistivity is calculated using electrode geometry, applied voltage, and measured current according to standard formulas.
Scope of ASTM D257 / IEC 62631-3-1
It can be applied to solid electrical insulating substances, such as polymers, elastomers, laminates, films, coatings, ceramics, and composites.
Defines the ways of measuring surface resistivity, volume resistivity, electrical resistance, and conductance.
Supports analysis over a broad range of resistivity between 104 and 1018 ohm units.
Applicable in both quality assurance and research.
Gives specifications about the types of electrodes, environmental control, and geometric corrections. Provides proper differentiation of surface leakage and bulk conduction processes.
ASTM D257 / IEC 62631-3-1 Equipment and Sample Preparation
Specimen details
ASTM D257 specimens are flat plates, rods, tapes, and tubes.
Specimen dimensions
The general sample size for ASTM is 20 mm.
Specimen preparation
Specimens are injection moulded or cut from moulded or extruded sheets or plates.
Use of ASTM D257 / IEC 62631-3-1
Aids in the selection of the materials to be used in the environment where high resistance to electrical leakage and the accumulation of electrical charge are important.
To control the quality of the production batch, it is used to ensure that the electrical behaviour remains constant across production batches.
Help determine the effects of moisture sensitivity and degradation on polymers and coatings.
Helps in the analysis of failures, differentiating between the surface and bulk material defects.
Common Challenges and Troubleshooting in ASTM D257 / IEC 62631-3-1
The typical ones are surface contamination, moisture uptake, and poor conditioning of the specimen, which may lead to unstable or wrongly low resistivity readings. Ensuring clean, dry materials; using controlled environments; proper orientation of electrodes; and frequent calibration of equipment address this problem, making results valid. Some time of stabilisation must be allowed, after which the current must be measured, especially for high-resistance materials.
ASTM D257 / IEC 62631-3-1 Testing Technique, Process, and Data Collection
A known DC voltage is applied to the specimen, and the current is measured at the end of the stabilisation. Surfaces and volume resistance are measured, and electrode geometry is corrected to obtain resistivity values. Environmental conditions, specimen conditioning time, applied voltages, stabilization times, and current readings are recorded in the data collection.
Analysis Results and Interpretation for ASTM D257 / IEC 62631-3-1
The outputs of the test give the quantitative measures of the surface resistivity and volume resistivity that can be used to measure the ability of a material to insulate or resist the flow of charge. Large values of volume resistivity imply that the material has a lot of insulation in its bulk, whereas large values of surface resistivity imply resistance to surface leakages and static dissipations. Interpretation would include comparing results to design requirements, establishing the impact of temperature or humidity, and evaluating the suitability of materials to high voltage or ESD sensitive requirements. These results can help engineers in the material qualification process, the prediction of the performance, and the prevention of failures.
Problem & The Solution for ASTM D257 / IEC 62631-3-1
One of the frequent issues is high variation in measurements caused by the impact of the environment, including humidity or contamination. It results in invalid resistivity information and misclassification of materials. Strict environmental control, such as a constant level of humidity, cleaning of the specimen, and increased conditioning time, is the answer.
Factors to Consider for ASTM D257 / IEC 62631-3-1
Speed: The automated electrometers and digital measurement systems are faster, and they have stable readings that stabilize faster.
Expert: Technicians with expertise will make the appropriate electrode configuration and environmental management, as well as proper interpretation of resistivity data.
Cost: Although it is costly to acquire, high-precision resistivity gadgets save on long-term failure, and high-precision testing saves on material costs, leading to high-cost savings.
You can share your astm d257 testing requirements with MaTestLab. MaTestLab has a vast network of material testing laboratories, spread across the USA and Canada. We support your all material testing needs ranging from specific astm d257 test to various testing techniques.
How much do I need to pay for the astm d257 test?
Please contact us for a detailed quote for your astm d257 testing needs. Cost incurred to carry out different astm d257 testing methodology depends on the type of raw material; number of samples, coupons, or specimens; test conditions, turn around time etc. Costs of some ASTM testing methods start from $100 and the final value depends upon the factors listed above. Please contact us for the best and latest prices.
How many samples are required for astm d257?
The required number of samples or specimens should comply with the procedure given in the astm d257 standard. However, the MaTestLab operations team can assist you for your special requirements once you share your testing details with us.
How much discount can I get on the astm d257 test?
MaTestLab has a vast testing laboratory network, hence we bring you the best testing facilities in a cost-effective way. We offer considerable discounts (15-20%) to our returning customers based on test volume and frequency.
How many days will it take to complete the astm d257 test?
The turnaround time for astm d257 test methodology depends upon the test procedure mentioned in the standard test document. However, we at MaTestLab understand your research requirements and hence try to get your test completed within the least possible time.
Where can I get the astm d257 tested?
You can share your astm d257 testing requirements with MaTestLab. MaTestLab has a vast network of material testing laboratories, spread across the USA and Canada. We support your all material testing needs ranging from specific astm d257 test to various testing techniques.
MaTestLab Inc. offers accessible, quick, and affordable material testing, product testing, and failure analysis services. We support your on-demand testing and expert consultation needs with the help of our extensive network of material testing laboratories situated in the US and other parts of the world.
MATERIAL TESTING
We offer destructive and non-destructive tests over a range of mechanical, electrical, chemical, thermal, optical, corrosion, radiation, and biological testing methodologies defined by ASTM, ISO and other organizations.
PRODUCT TESTING
We help you evaluate and ensure your product quality and performance with standard and custom-made testing solutions. All the tests are done at well-equipped testing laboratories using standard testing methods for best output and satisfaction.
FAILURE ANALYSIS
Failure analysis ensures high levels of quality in every manufacturing process. We help you with getting the best failure or root cause analysis to determine the cause of the failure. The results help you identify means to prevent failure recurrences.
