Labconco Bulk Powder Stations 3962622 - Manual (Page 8)

Chapter 2: Prerequisites
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Support, Vibration and Movement Requirements
The XPert Bulk Powder Enclosures all come standard with a support stand, electric
lift and stainless steel work surface.
The ability for analytical balances to accommodate vibration varies with type and
brand. More advanced balances have improved vibration compensation; however
in the preparation of a balance enclosure site, please consider the following:
 The corners of a building typically have less vibration than the center.
 The work surface with the Bulk Powder Enclosure should not contain any
vibration-producing equipment, such as shakers or pumps.
 Although the enclosure’s work surface is a very stable platform, adding a
marble slab with dampening pads is also an effective low cost means of
controlling vibration.
Temperature Variation Requirements
The extent the balance readings are influenced by temperature variations is a
function of the balance design. Most manufacturers would suggest that a
temperature drift of 1-2°C is generally tolerable. Only validation through your
Operational Qualification protocol can define what is acceptable. To minimize the
potential for temperature variations:
 Never install balances near heating sources such as radiators and hot plates.
 Avoid incandescent lighting of the enclosure where radiant heat produced will
raise temperatures. (See Chapter 7 for adding an accessory fluorescent light
kit to models without a light).
 Do not place the enclosure in a location that would receive direct sunlight.
Humidity and Static Electricity Requirements
Electrostatics can be troublesome in a balance enclosure. It is important to
understand and, to the extent possible, control static charges. An electrostatic
charged vessel, sample or enclosure can apply forces and lead to errors in
weighing. The repulsion or attraction can be detected with micro, semi micro and
analytical balances. Static charges can also lead to particulates being attracted to
surfaces within the balance enclosure. Containment of harmful powders,
prevention of cross-contamination and clean up are all enhanced when static
attraction of powders is minimized. The construction of the XPert Bulk Powder
Enclosure avoids the use of plastics, which are highly insulative. The advantages
to the glass and epoxy-coated metal construction are twofold.
1.
The enclosure does not contribute high electrostatic forces affecting the
precision of the balance.
2.
The attraction and ultimate accumulation of powder (hazardous or
nuisance) are minimized on the inside of the enclosure.