DIN EN 61340-2-1:2016-07

Measurements of the dissipation rate of static charge for various materials are among the essential measurement techniques in the field of electrostatics. For homogeneous conductive materials, this property can be assessed indirectly by resistance measurements or by resistivity measurements. Care must be taken when determining the homogeneity of materials, since some materials exhibit inhomogeneous electrical characteristics even though they appear homogeneous. If the homogeneity of the material is not known and cannot otherwise be traced, resistance measurements may not be reliable enough or provide sufficient information. For materials in the dissipative or insulating range, and especially for high-resistance materials containing conductive fibers (for example, textiles with a metallic grid), resistance measurements may also not be reliable enough. In such cases, the static charge dissipation rate shall be measured directly. This Part 2-1 of the IEC 61340 series of International Standards describes test methods for measuring the rate of dissipation of static charge of insulating and static dissipative materials and products. It includes a generic description of test methods and detailed test procedures for specific applications. The two test methods for measuring charge decay time, one using corona charging and one using a charged metal plate are different and may not give equivalent results. Nevertheless, each method has a range of applications for which it is best suited. The corona charging method is suitable for evaluating the ability of materials, for example textiles, packaging, etcetera, to dissipate charge from their own surfaces. The charged metal plate method is suitable for evaluating the ability of materials and objects such as gloves, finger cots, hand tools, etcetera, to dissipate charge from conductive objects placed on or in contact with them. The charged plate method may not be suitable for evaluating the ability of materials to dissipate charge from their own surfaces. In addition to its general application, this horizontal standard is also intended for use by technical committees in the preparation of standards in accordance with the principles laid down in IEC Guide 108. One of the responsibilities of a technical committee is, wherever applicable, to make use of horizontal standards in the preparation of its publications. The contents of this horizontal standard shall not apply unless specifically referred to or included in the relevant publications. Two procedures are described. The first procedure determines the dissipation of charge applied to the surface of the material by corona discharge. The subsequent decrease in surface potential is observed with a field strength meter or other suitable device. This method is applicable for measuring the charge decay of surfaces and materials. The second method determines the charge dissipation from a charged plate through an object under test by applying a potential to the metallic plate, disconnecting the voltage source, and observing the decrease in the potential of the plate with a field strength meter or other suitable device. This method is applicable for measuring charge decay across products such as finger cots, gloves, and hand tools. In addition to the charging methods described here, there are of course other methods of charging materials (for example, friction electric charging or charging by induction), but these are not relevant to this document. The test methods described in this International Standard use high voltage sources that can present hazards if used improperly, especially by unqualified or inexperienced personnel. Users of this International Standard are encouraged to perform appropriate risk assessments and follow local regulations before using the methods described herein. The responsible committee is DKE/K 185 "Elektrostatik" ("Electrostatics") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.