# Which is Better: Three or Four Load Cells?

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INTRODUCTION
It is a commonly asked question: Is it better to use three or four load cells on a scale?
In theory, you can use any number of load points (load cells) to support a vessel. The actual number
used is dependent upon these factors:
• The vessel’s geometry (shape and number of supports).
• The vessel’s gross weight (both live and dead weight).
• The vessel’s structural strength.
• The environment in which the vessel is located.
• What is available structurally to provide a stable, load-bearing support.
• The characteristics of the material being weighed.
3 White Paper • Which is Better: Three or Four Load Cells?
For short, upright cylindrical vessels in a compression installation, three load cells spaced at 120°
intervals provide the most convenient support. Three-leg weighing systems balance like a tripod, with
load distribution being virtually automatic, and they only require minor balancing at installation. You
must install all of the load cells in the same plane within 3° of each other.
Cylindrical vessels suspended symmetrically in tension with three load cells provide the advantage of
equally distributing the load among the load cells. What is available structurally is important in this
situation.
A vessel in tension can be hung in a corner where there are two supporting structures at right angles.
All it requires is a 45° cross brace to provide support for the third load point. Of course, the support
beams must be sufficiently strong and stiff to support not only the fully loaded vessel, but also other
vessels that may be supported from the same structure, and any changes in the structural load, such as
an accumulation of snow, water or ice.
A vessel in tension can be hung in a corner where there are two supporting structures at right angles.
All it requires is a 45° cross brace to provide support for the third load cell. Of course, the support
beams must be sufficiently strong and stiff to support not only the fully loaded vessel, but also other
vessels that may be supported from the same structure, and any changes in the structural load, such as
an accumulation of snow, water or ice.