ANSI ESD STM 3.1:2000 pdf free download – for Protection of Electrostatic Discharge Susceptible Items- Ionization
1.1 Scope
This standard test method establishes measurement techniques, under specified conditions, to determine ion balance and charge neutralization time for ionizers. This standard test method does not include measurements of electromagnetic interference (EMI)， or uses of ionizers connection with ordnance, flammables, explosive items or electrically initiated explosive devices.
1.2 Purpose
This standard test method provides test methods and procedures for evaluating and selecting air ionization equipment and systems (ionizers). 1.3 Application As contained in this standard test method, the test methods and test conditions may be used by manufacturers of ionizers to provide performance data describing their products. Users of ionizers are urged to modifty the test methods and test conditions for their specific application in order to qualify ionizers for use, or to make periodic verifications of ionizer performance. The user will need to decide the extent of the data required for each application.
3 Definitions
The following definitions apply for the purposes of this document in addition to those specified in ESD ADV-1.0 – Glossary: air conductivity: The ability of air to conduct (pass) an electric current under the influence of an electric field. air ions: Molecular clusters of about 10 molecules (water， impurities, etc.) bound by polarization forces to a singly charged oxygen or nitrogen molecule. charge decay: The decrease and/or neutralization of a net electrostatic charge. charge induction: The redistribution of charge in an isolated conductor when placed in an electric field (for example, from a charged body). Note: Momentary grounding of such a conductor would result in its gaining a net charge. charged plate monitor (CPM): An instrument used to measure the charge neutralization properties of ionization equipment. compressed gas ionizer: lonization devices that can be used to neutralize charged surfaces and/or remove surface particles with pressurized gas. This type of ionizer may be used to ionize the gas within production equipment. corona: The production of positive and negative ions by a very localized high electric field. The field is normally established by applying a high voltage to a conductor in the shape of a sharp point or wire. decay rate: The decrease of charge or voltage per unit time. discharge time: The time necessary for a voltage (due to an electrostatic charge) to decay from an initial value to some arbitrarily chosen final value.
laminar flow hood ionization: These devices or systems provide local area ionization coverage in vertical or horizontal laminar flow hoods or benches. offset voltage: The observed voltage on the isolated conductive plate of a charged plate monitor that has been placed in an ionized environment. peak offset voltage: For pulsed ionizers, the maximum value of the offset voltage for each polarity, as the ionizer cycles between positive and negative ion outputs. room ionization: lonization systems that provide large area coverage with air ions. worksurface ionization (formerly tabletop ionization): lonization devices or systems used to control static charges at a workstation. Note: This type includes benchtop ionizers, overhead worksurface ionizers, and laminar flow hood ionizers. vertical laminar flow: Non-turbulent arflow in a vertical direction.