Location and air current requirements, Background on electrostatics or static electricity – Labconco XVS Ventilation Stations 4865060 User Manual

Page 9

Chapter 2: Prerequisites

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Background on Electrostatics or Static Electricity

Electrostatic charges on a surface such as the wall of a balance enclosure are
not created by moving air. Gases do not cause the charge. Impurities within
the air impinging upon surfaces dictate the polarity and magnitude of the
charge. The process, triboelectrification, occurs when the friction of the dust
particles contact the surface and electrons move across the interface.

The ability of a material to become polarized is a property known as
permittivity. On highly insulative materials like acrylic, ions or charged
molecules are strongly bound to the surface by polarization forces. The
higher the force, the higher is the permittivity value of the material. It is
suggested that the use of high permittivity materials, such as plastic be
avoided.

Since static electricity is a surface phenomenon, materials can also be
classified by their surface resistivity measured in ohms per square. The table
below lists the surface resistivity of various classes of material.

Surface Resistivity Table

Material

Surface Resistivity

Example

Conductive

→ 10

Ω per square

Skin, Metals

Static dissipative

→ 10

Ω per square

Glass

Antistatic

→ 10

Ω per square

Polyethylene bag

Insulative

Ω per square→

Acrylic, Packing foam, Styrofoam

Location and Air Current Requirements

The XPert Balance Enclosure and XVS Ventilation Station both have been
designed to contain hazards by negating typical cross drafts and movements
within the opening. Air movement does not affect most modern balances
with draft shields. However, as a precautionary measure of safety and a
higher level of quality management, it is recommended that the enclosure be
placed in such an area to avoid:

• High traffic areas where walking might cause an air disturbance or be a

nuisance to balance readings.

• Overhead or wall HVAC diffusers, fans, radiators or other lab equipment

producing air currents.

• Next to doorways or windows that may be opened.

This manual is related to the following products:

XVS Ventilation Stations 4865022 XVS Ventilation Stations 4865021 XVS Ventilation Stations 4865012 XVS Ventilation Stations 4865011 XVS Ventilation Stations 4865010 XVS Ventilation Stations 4864042 XVS Ventilation Stations 4864041 XVS Ventilation Stations 4864032 XVS Ventilation Stations 4864031 XVS Ventilation Stations 4864030 XVS Ventilation Stations 4864022 XVS Ventilation Stations 4864021 XVS Ventilation Stations 4864012 XVS Ventilation Stations 4864011 XVS Ventilation Stations 4864010 XVS Ventilation Stations 4863042 XVS Ventilation Stations 4863041 XVS Ventilation Stations 4863032 XVS Ventilation Stations 4863031 XVS Ventilation Stations 4863030 XVS Ventilation Stations 4863022 XVS Ventilation Stations 4863021 XVS Ventilation Stations 4863012 XVS Ventilation Stations 4863011 XVS Ventilation Stations 4863010 XVS Ventilation Stations 4862042 XVS Ventilation Stations 4862041 XVS Ventilation Stations 4862032 XVS Ventilation Stations 4862031 XVS Ventilation Stations 4862030 XVS Ventilation Stations 4862022 XVS Ventilation Stations 4862021 XVS Ventilation Stations 4862012 XVS Ventilation Stations 4862011 XVS Ventilation Stations 4862010 XPert Balance Enclosures 3971872 XPert Balance Enclosures 3971871 XPert Balance Enclosures 3971862 XPert Balance Enclosures 3971861 XPert Balance Enclosures 3971860 XPert Balance Enclosures 3971842 XPert Balance Enclosures 3971841 XPert Balance Enclosures 3971832 XPert Balance Enclosures 3971831 XPert Balance Enclosures 3971830 XPert Balance Enclosures 3971822 XPert Balance Enclosures 3971821 XPert Balance Enclosures 3971802 XPert Balance Enclosures 3971801 XPert Balance Enclosures 3971800 XPert Balance Enclosures 3971672 XPert Balance Enclosures 3971671 XPert Balance Enclosures 3971662 XPert Balance Enclosures 3971661 XPert Balance Enclosures 3971660 XPert Balance Enclosures 3971642 XPert Balance Enclosures 3971641 XPert Balance Enclosures 3971632 XPert Balance Enclosures 3971631 XPert Balance Enclosures 3971630 XPert Balance Enclosures 3971622 XPert Balance Enclosures 3971621 XPert Balance Enclosures 3971602 XPert Balance Enclosures 3971601 XPert Balance Enclosures 3971600 XPert Balance Enclosures 3971572 XPert Balance Enclosures 3971571 XPert Balance Enclosures 3971562 XPert Balance Enclosures 3971561 XPert Balance Enclosures 3971560 XPert Balance Enclosures 3971542 XPert Balance Enclosures 3971541 XPert Balance Enclosures 3971532 XPert Balance Enclosures 3971531 XPert Balance Enclosures 3971530 XPert Balance Enclosures 3971522 XPert Balance Enclosures 3971521 XPert Balance Enclosures 3971502 XPert Balance Enclosures 3971501 XPert Balance Enclosures 3971500 XPert Balance Enclosures 3930442 XPert Balance Enclosures 3030441 XPert Balance Enclosures 3930432 XPert Balance Enclosures 3930431 XPert Balance Enclosures 3930430 XPert Balance Enclosures 3930422 XPert Balance Enclosures 3930421 XPert Balance Enclosures 3930402 XPert Balance Enclosures 3930401 XPert Balance Enclosures 3930400 XPert Balance Enclosures 3930342 XPert Balance Enclosures 3030341 XPert Balance Enclosures 3930332 XPert Balance Enclosures 3930331 XPert Balance Enclosures 3930330 XPert Balance Enclosures 3930322 XPert Balance Enclosures 3930321 XPert Balance Enclosures 3930302 XPert Balance Enclosures 3930301 XPert Balance Enclosures 3930300 XPert Balance Enclosures 3930242 XPert Balance Enclosures 3030241 XPert Balance Enclosures 3930232 XPert Balance Enclosures 3930231 XPert Balance Enclosures 3930230 XPert Balance Enclosures 3930222 XPert Balance Enclosures 3930221 XPert Balance Enclosures 3930202 XPert Balance Enclosures 3930201 XPert Balance Enclosures 3930200