Spark testing of geomembrane field seams is particularly useful in locations where other nondestructive test methods are not practical, for example in tight corners or a circumferential seam around a pipe.

1.1 This practice covers the nondestructive testing of field seams in geomembranes using the spark test. A suspect area is indicated by the generation of a spark. The test is applicable to seams made by the extrusion method, seams made by using welding tape (a strip of the same type of material as the geomembrane, that is welded over adjacent sections of geomembrane to create a seam), or seams where it is practical to insert a conductive material in the seam just prior to or during fabrication.

1.2 The spark test may produce an electrical spark and therefore can only be used where an electrical spark would not create a hazard.

1.3 Unless the voltages and distances prescribed are carefully adhered to, a “false positive” indication may result. This false positive occurs when the arc distance is too large for the voltage applied at the time and conditions of testing.

1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate health and safety practices and to determine the applicability of regulatory limitations prior to use.