Environmental factors influencing the weighing of tanks or silos

Wind and seismic forces can have a great effect on outdoor weighing system. Upward, downward, and shear forces are exerted on load cells.

• Use larger capacity load cells to accommodate for the added loads.
• Mechanical restraints can be applied to maintain the scale’s position.

Wind effect

The effect of wind are complex and depend on factors such as the degree of exposure, local topography and maximum wind speed.

Wind striking an exposed tank or silo will generate a side force which causes an overturning moment and a smaller vertical force.

• When the silo is empty: The wind force may be sufficiently strong to overturn the structure.
• When the silo is full: The combination of the overturning force reaction, and the total weight of the silo, may generate load cells overloading.

Moisture and corrosive substances can damage the cells physically and by shorting out its electronics. Debris collected on the load cells will cause weighing errors by mechanically binding the scale.

• Provide adequate drainage away from the cells.
• Regularly clean accumulated debris. Keep cables clean and in good condition.
• Protect cells and cables from corrosive materials.

Caused by the surrounding environment or mixer’s agitation, vibration Induces electrical noise on the load cell’s signal.

• Separate the surrounding structure from the load cell supports.
• Use isolation pads between the load cells and structure.

Temperature can affect a load cell by causing structural supports to expand and contract or by exceeding the operating limits of the load cell.

As a tank expands and contracts, it pushes or pulls on attached piping. If the piping connections are rigid, this can cause weighing errors.

• Use device allowing structural expansion.
• Use insulation material between the cells and the tank.

A load dropped on the scale from above can exert strong forces that can damage the load cells.

• Use larger capacity load cells to accommodate for large shock loads.
• Use shock absorbing materials to damp the loading.

Electrical surges can cause permanent damage to the load cells. Electrical surges may be caused by lightning, large electrical machines or welding.

• Verify the integrity of any existing grounding systems.
• Use a single-point grounding system and surge protection devices.
• Don't carry out electric welding near load cells

Every load cell should be shunted by a stranded copper cable to prevent welding currents from flowing through the load cell.