ANSI/ESD Test Methods Are Different than EU Standards
ANSI/ESD S7.1 versus EN 1081
A military electronics company trying to meet static control requirements in ANSI/ESD S20.20-2007 contacted us about a problem they were having with their new floor. The new floor was purchased under the assumption that it would meet all the requirements of Table 2 in the S20.20 document. The caller explained that the floor wasn’t meeting any of the requirements even though the manufacturer assured them nothing was wrong with it. They described the floor as a static conductive linoleum sheet floor. After reviewing the clients test data I agreed to meet with and help them find out why the floor wasn’t doing what it was supposed to do.
Immediately after I arrived, I was asked to measure the floor with my meter, a Prostat megohm meter. After several tests, we concluded that the floor was incapable of meeting any of the S20.20 requirements; it was far too resistive The resistance to ground exceeded 1 billion ohms (1.0 X 10 E9.) The system resistance exceeded 3.5 X 10 E7. The building representative was extremely agitated because they knew it would be difficult to shut down the facility and replace the floor. They told me they were guaranteed that this floor would do everything they required. After a quick review of the floor manufacturer’s documents we discovered the real problem with the floor. The manufacturer’s specifications referenced a resistive test method call EN 1081. Unlike North American method ANSI/ESD S7.1, the European method tests floors using a much higher applied voltage. EN1081 actually references an applied voltage of 500 volts. Higher applied voltages cause the resistance to drop. Using our methods, the floor measured extremely high. Unfortunately for this end user, they were probably stuck with the floor without recourse because no one in their organization had picked up on the test method used by the European manufacturer. It was clearly printed on their spec sheet.
A word of advice: Always ask for domestic independent test data when qualifying any kind of static control flooring. Additionally, require a post installation certification demonstrating that the flooring meets Method One in ANSI/ESD S20.20 for Personnel grounding. Method One utilizes ANSI/ESD S97.1 System resistance testing. An acceptable system resistance measures below 3.5 X 10 E7 ohms. You might also take a look at this video for further understanding.
Comments