Aggregate Weigh Hopper Load Cell

Function

Accurate aggregate weighing is the primary determinant of concrete mix proportioning. A calibrated load cell set holding ±0.1–0.2% combined accuracy over the working range ensures consistent water-to-cement and aggregate-to-cement ratios batch after batch, meeting the tolerances demanded by structural concrete mix designs. Cell overloading, thermal drift, or moisture-induced zero shift produces systematic batching errors that are invisible to the operator at the plant but become apparent only when cube test results deteriorate — at considerable commercial and reputational cost to the contractor.

Construction & quality

Cells are machined from alloy steel (17-4 PH stainless steel or precision tool steel) and heat-treated for elastic stability. The sensing element is a 350 Ω four-arm full Wheatstone bridge, bonded with precision adhesive, encapsulated in silicone gel, and hermetically sealed to IP67 as minimum (IP68 submersible option for flooded-pit installations). Cable entry is double-sealed with a stainless conduit adaptor. Each cell is individually calibrated over at least three load points; the calibration certificate is traceable to national mass standards and records combined error, creep, and temperature coefficient.

When to replace

• Batch aggregate weight consistently offset positive or negative versus set-point without process change
• Calibration drift detected at daily zero-check or span verification
• Physical damage, visible crack, or body deformation on cell inspection
• Moisture ingress causing unstable, fluctuating, or noisy digital weight display
• Overload event logged in the batch controller following hopper impact or filling error