ANSI STM4.1:2017 pdf download.The Protection of Electrostatic Discharge Susceptible Items Worksurfaces -Resistance Measurements(Including Shelving and Mobile Equipment).
This document establishes methods for resistance measurements of worksurfaces, shelving and mobile equipment used at workstations where protection of ESD susceptible items is required.
3.0 REFERENCED DOCUMENTS
Unless otherwise specified, the following documents of the latest issue, revision, or amendment form a part of this document to the extent specified herein: ESD ADV1 .0, ESD Association’s Glossary of Terms
ASTM D257, Standard Test Method for D-C Resistance or Conductance of Insulating Materials
4.0 DEFINITION OF TERMS
The terms used in the body of this document are in accordance with the definitions found in ESD
ADV1 .0, ESD Association’s Glossary of Terms available for complimentary download at www.esda.org.
5.0 PERSONNEL SAFETY
THE PROCEDURES AND EQUIPMENT DESCRIBED IN THIS DOCUMENT MAY EXPOSE PERSONNEL TO HAZARDOUS ELECTRICAL CONDITIONS. USERS OF THIS DOCUMENT ARE RESPONSIBLE FOR SELECTING EQUIPMENT THAT COMPLIES WITH APPLICABLE LAWS, REGULATORY CODES, AND BOTH EXTERNAL AND INTERNAL POLICY. USERS ARE CAUTIONED THAT THIS DOCUMENT CANNOT REPLACE OR SUPERSEDE ANY
REQUIREMENTS FOR PERSONNEL SAFETY. GROUND FAULT CIRCUIT INTERRUPTERS (GFCI) AND OTHER SAFETY PROTECTION SHOULD BE CONSIDERED WHEREVER PERSONNEL MIGHT COME INTO CONTACT WITH ELECTRICAL SOURCES. ELECTRICAL HAZARD REDUCTION PRACTICES SHALL BE EXERCISED AND PROPER GROUNDING INSTRUCTIONS FOR EQUIPMENT SHOULD BE FOLLOWED.
THE RESISTANCE MEASUREMENTS OBTAINED THROUGH THE USE OF THIS TEST METHOD SHALL NOT BE USED TO DETERMINE THE RELATIVE SAFETY OF PERSONNEL EXPOSED TO HIGH AC OR DC VOLTAGES.
Conductive rubber electrodes are used for material evaluation and qualification.
NOTE: Over time, conductive rubber materials used as the contact surface of the electrodes can warp. This could cause measurements to change. At this time there is no standardized method to verify if this has occurred but the user should be aware of this phenomenon.
6.2 Stainless Steel Plate
One (1) stainless steel plate, with suggested dimensions of 127 mm x 254 mm x 1.57 mm thick (5 inches x 10 inches x 0.06 inch thick), or of sufficient thickness to support the weight of the specimen without becoming distorted.
6.3 Insulative Support Surface
A planar (flat) surface, when used for specimen support, shall have a surface resistivity greater than 1.0 x 1013 ohms/square when measured per ASTM D257 or a surface resistance greater than 1.0 x 1012 ohms when measured per ANSI/ESD STM1 1.11.
For test methods using 2.27 kg (5 lb ± 2.5%), 63.5 mm ± 5% (2.5 inch ± 5%) electrodes, an alternate method to verify the properties of the specimen support surface may be used, by measuring the resistance point-to-point of the material with the electrodes spaced at least 152 mm (6 inches) apart (edge-to-edge). A resistance point-to-point of at least one order of magnitude greater than the upper limit of the item being measured is required.
6.4 Resistance Measurement Apparatus
The measurement apparatus, called the meter, whether it is a single meter or a collection of instruments that are capable of the following.ANSI STM4.1 pdf download.