ETS evaluates the electrostatic characteristics of materials and products using resistance/resistivity, static decay, static shielding and triboelectric (or corona charging) test methods. Tests are performed at ambient or controlled-environment conditions, and ETS’ facilities include microprocessor-controlled humidity chambers and a controlled environment room. ETS tests a broad range of products across various industries.
ESD Material Testing Laboratory Services
Surface Resistance and Surface Resistivity are the most common tests for measuring the surface of liquids, powders, sample material plaques, or finished products. These tests are intended to predict the ability to bleed off or retain static charge using industry standard or custom test fixtures. Resistivity (when appropriate) is calculated from the measured resistance using the dimensions of the electrodes and/or test sample.
Volume Resistance and Volume Resistivity are the most common tests for measuring through the thickness of liquids, powders, sample material plaques, or finished products. These tests are also intended to predict the ability to bleed off or retain static charge using industry standard or custom test fixtures. Resistivity (when appropriate) is calculated from the measured resistance using the dimensions of the electrodes and/or test sample plus the thickness of the sample.
ETS can perform testing using virtually any standard or test method, although most testing is performed in accordance with the following commercial and military standards:
- ESD Association (ANSI/ESDA STM 4.1, 11.11, 11.12, 11.13),
- ASTM (D-257, D-991 and F-150),
- NFPA (99, and 77)
- Mil-PRF 81705F
Static Decay measures the ability of a material to dissipate an applied charge when grounded. Samples are electrically charged to ±5kV, and we measure the time required for the charge to bleed off to either the 10% or 1% level. Variations of this procedure are used to evaluate many types of material and finished products, including:
- Completed parts or assemblies;
- Packaging materials;
- Woven and non-woven materials;
- Labels and films;
- Garments and gloves;
- Flooring; and
- Work surfaces.
SAE J1645 for automotive fuel systems is an example of a specification that uses this measurement technique. We can also measure the time a material retains an applied charge (commonly referred to as charge retention).
ETS can perform testing using virtually any standard or test method. We can deliver results in accordance with, but not limited to, the following commercial and military standards:
- Federal Test Method Standard (FTMS) 101C, Method 4046
- Mil PRF 81705F
- Mil C 83429B
- Method 5931
- BS (British Standard) 7506
Triboelectric Charge Generation evaluates the ability of material or objects to generate charge when rubbed against or separated from another material, or from itself. The variables that can affect these measurements include material relationship on the triboelectric scale, environmental, mechanical, electrical, and data interpretation. ETS obtains data using nanocoulombmeters, charge plate monitors, and high-speed oscilloscopes.
ESDA Adv 11.2 describes several test methods, including the inclined plane test that measures the charge buildup on quartz and Teflon® cylinders rolled down a 12” (305mm) material sample mounted on a grounded surface inclined at 15°.
- Compliance Tests: 6 samples using 6 of each cylinder type
- Indication Tests: 6 samples using 3 of each cylinder type
USPS-T-3204 Sec. 3.1.8 Electrostatic (Static Charge) testing of mailer film: Standard defining the maximum charge developed when mailer film wrapped around a standard 8 ½ x 11” tablet is separated from another tablet. The test procedure specifies a maximum of +/- 2000 volts be generated in the laboratory testing.
In addition to testing using these methods, ETS has helped manufacturers develop test procedures and performance criteria for Labels and other products that may be utilized in applications that affect safety and performance.
Static Shielding per ESD STM11.31 (Energy) – This test measures the energy inside a static shielding bag. A 1kV Human Body Model (HBM) discharge is applied to the outside surface of a bag clamped between discharge, capacitive sensor, and ground electrodes, and the ESD pulse that penetrates the bag is measured.
The ETS Test Suite Manager program generates a complete report of the peak current and energy measured inside the bag in accordance with ESDA STM 11.31.
- Compliance Tests: 12 samples (6 at 12% & 6 at 50% RH)
Individual Specimens (Tested at 12% & 50% RH)
- Indication Tests: (Tested at one R.H. level)