Belt Weigher System

What is a Belt Weigher System?

Load cells measure the force carried by a weigh idler or weighbridge, while a speed sensor supplies belt travel. An integrator combines both signals to calculate instantaneous flow rate and accumulated total. Accuracy depends on the full mechanical installation, not only the electronics.

A complete installation is selected by function rather than product name. Mechanical action, contact behavior, reset method and environmental capability must match the monitored hazard or process condition, while the control circuit determines whether the signal becomes an indication, alarm, interlock or stop.

Typical applications

This product type is frequently considered for production accounting, process control, loading and blending, inventory reconciliation. Selection should reflect both the intended signal and the practical ability to inspect, test and replace the installed unit safely.

• production accounting: verify the actual operating condition, mounting geometry and required response before selecting a model.
• process control: verify the actual operating condition, mounting geometry and required response before selecting a model.
• loading and blending: verify the actual operating condition, mounting geometry and required response before selecting a model.
• inventory reconciliation: verify the actual operating condition, mounting geometry and required response before selecting a model.

How to select the right model

For a new application, specify geometry and response from the conveyor design. For a replacement, capture the complete old code, terminals, actuator and mounting before removal, then verify any proposed successor against the original function.

Create an equipment record containing the full model code, approved datasheet, terminal plan and selected settings. This makes quotations comparable and preserves the engineering basis for later replacement.

• Confirm the contact arrangement, utilization category and control voltage.
• Match the enclosure and ingress rating to dust, water, washdown and corrosion exposure.
• Check ambient temperature, cable entry, mounting dimensions and actuator geometry.
• For hazardous areas, verify the complete certificate and marking for the exact model.

Installation and commissioning guidance

Install the weighbridge on a stable, straight conveyor section with consistent belt tension and suitable idlers. Complete zero and span calibration under the manufacturer’s procedure and verify performance with a material test when required.

Use a rigid, low-vibration support and keep the actuator inside its specified approach and overtravel. Preserve sealing and earthing with compatible glands, then test the signal from the physical device through to the final control action.

Inspection and lifecycle care

Set maintenance frequency from risk, environment, duty and failure history. Devices that rarely operate in production still require planned proof tests because the absence of alarms does not demonstrate health.

Never bridge or restrain a protective device to maintain production. Control the affected equipment, investigate the initiating condition and restore normal service only after corrective work and a successful test.

Specification, commissioning and lifecycle record

A dependable belt weigher system decision remains traceable from the operating requirement to the installed order code. Record the normal condition, abnormal trigger, required controller state, alarm or stop response, reset rule and inspection method before requesting quotations. This prevents commercial substitutions from changing the engineering function unnoticed.

Keep the approved datasheet, complete model suffix, terminal drawing, mounting sketch, certificates and commissioning result under the equipment tag. After replacement, adjustment, conveyor modification or control-software change, repeat the relevant physical proof test and update the as-built record. The test must demonstrate the field device, wiring, controller indication and final machine response rather than only a changing PLC input.

• Compare complete order codes and option suffixes.
• Confirm contact state under normal, actuated and fault conditions.
• Record the installed clearance, angle, tension, threshold or calibration.
• Inspect mounting, cable entries, seals, earthing and access.
• Set maintenance intervals from risk, environment, duty and failure history.

Frequently asked questions

What causes belt scale zero drift?

Material buildup, changing belt tension, misaligned idlers, temperature effects, mechanical binding and speed-signal problems are common causes.

Is a test weight calibration enough?

It checks much of the measuring chain, but a controlled material test is often the strongest confirmation of total system accuracy.