What happens during a belt weigher calibration visit?

A belt weigher calibration visit is more than changing a number in an integrator. Accurate Industries plans the work with your site, inspects and services the weighing system, records the equipment condition and operating data, completes the appropriate calibration checks, and reports what was found and what may need attention next.

A belt weigher is also called a weightometer, conveyor belt scale, or belt scale. The purpose of a calibration visit is to help ensure the tonnes recorded by the equipment remain useful for production, stock control, reconciliation, and operational decisions.

What happens before the visit?

Good calibration work starts before the technician reaches the conveyor. Accurate Industries works with your site to understand the equipment, application, access requirements, and available operating windows.

Planning may include:

• confirming the belt weigher, weightometer, or conveyor belt scale make and model;
• reviewing the reason for the visit, such as routine calibration, poor readings, a fault, a relocation, or follow-up work;
• confirming site access, inductions, permits, escorts, and required competencies;
• agreeing isolation and access arrangements with the authorised site personnel;
• planning time to run the belt empty for zero checks;
• arranging controlled feed or material access if a material comparison is required;
• confirming whether lifting equipment, an elevated work platform, a crane, traffic control, or a laydown area may be needed; and
• identifying shutdown constraints and the people who need to be available on the day.

The exact requirements depend on the site and the scope of work. Agreeing these details early helps prevent avoidable delays.

What happens when the technician arrives on site?

The visit begins with the site’s access and safety process. This may include sign-in, site induction, permits, a job safety analysis, toolbox discussions, isolation procedures, and confirmation of the work area.

The technician will confirm the equipment to be worked on and discuss any operating issues reported by the site team. If the condition of the equipment or the site differs from the information provided during planning, the scope may need to be adjusted before work continues.

Why is the complete installation inspected first?

A calibration cannot correct every mechanical or electrical problem. If the belt weigher is calibrated over a fault, the result may look acceptable during the visit but become unreliable again when the underlying problem changes.

The inspection considers the complete weighing system, including:

• the weigh frame and mounting points;
• load cells and load-cell connections;
• weigh idlers, approach idlers, and retreat idlers;
• rollers, bearings, shafts, and frames;
• belt tracking, belt condition, and belt tension;
• the speed sensor and its mounting;
• cabling, junction boxes, glands, terminations, and earthing;
• the integrator, display, communications, and relevant settings;
• material build-up, carryback, spillage, and obstructions; and
• the surrounding structure, vibration, access, and guarding.

The inspection helps separate a calibration issue from a mechanical, electrical, belt, structural, or operating issue.

What servicing can be included?

The service completed during a calibration visit depends on the equipment, access, condition, site requirements, and agreed scope. Where practical and safe, work may include:

• cleaning material build-up, carryback, dust, and spillage from the weighing area;
• cleaning components, mounts, junction boxes, and accessible equipment surfaces;
• inspecting rollers, bearings, idlers, load cells, cables, sensors, and mounting hardware;
• checking and correcting alignment where adjustment is available;
• lubricating or regreasing components where the equipment and manufacturer requirements call for it;
• tightening, adjusting, or repairing accessible components;
• checking sensor mounting and speed measurement;
• identifying worn, damaged, seized, or unreliable components;
• replacing components where this is included in the scope and parts are available; and
• recording repairs, recommendations, parts required, and follow-up work.

Some repairs require additional parts, lifting equipment, a shutdown, structural work, or a separate quotation. If a problem cannot be corrected during the planned visit, Accurate Industries will explain what was found and what is required next.

What information is recorded?

Recording the condition and readings creates a useful reference for future service. Depending on the system and scope, the technician may record:

• equipment make, model, serial number, and configuration;
• belt width, belt speed, belt length, and relevant operating details;
• integrator and speed-sensor information;
• weigh frame, load-cell, idler, and junction-box details;
• belt and mechanical condition;
• build-up, carryback, tracking, and housekeeping observations;
• zero, span, repeatability, and functional test results;
• as-found and as-left settings or readings;
• repairs, adjustments, cleaning, and parts used;
• photographs of components or conditions requiring attention; and
• recommendations, upcoming requirements, and follow-up actions.

The information recorded depends on the equipment and the agreed service scope. The goal is to leave a clear record of what was checked, what was found, what was changed, and what should happen next.

How is the zero checked?

Zero is the reading from the belt weigher when the belt is running without material. The technician may run the empty belt for several revolutions so belt variation, joins, thickness changes, and other effects can be observed.

The as-found zero shows how the system was reading before service. If the zero is outside the expected range or is unstable, the technician investigates possible causes such as build-up, rollers, belt tracking, belt movement, load-cell issues, structural movement, or electrical noise.

After relevant issues have been addressed, the zero may be adjusted in accordance with the equipment and calibration procedure. The resulting as-left value is recorded.

How is the span checked?

Span is the part of the calibration that checks how the system responds to a known load. The method depends on the belt weigher design, site conditions, and purpose of the test.

Depending on the system, the check may use:

• known test weights or billets applied to the weighing equipment;
• a calibration chain or another approved test device; or
• a controlled material comparison against a separately established reference.

The technician records the as-found result, the adjustments made, and the as-left result. If a material comparison is used, the test conditions and reference method are important to interpreting the result.

Why are repeatability and functional checks important?

A single acceptable reading does not necessarily show that a belt weigher will remain stable in production. Repeatability checks help show how consistently the system responds when comparable conditions are repeated.

Functional checks may also confirm that the belt speed signal, load measurement, integrator, alarms, outputs, totalisers, and relevant communications are operating as expected. The checks completed depend on the system and the scope of the visit.

If the results are inconsistent, the technician returns to the inspection findings to identify what may be moving, binding, vibrating, drifting, or producing an unreliable signal.

What happens if repairs are needed?

If the inspection identifies a problem, Accurate Industries will explain whether it can be corrected during the visit or whether it requires additional work.

Possible follow-up work may include:

• cleaning or removing build-up;
• replacing worn rollers, bearings, load cells, cables, sensors, or other components;
• repairing or improving mounts and structure;
• correcting belt tracking or idler alignment;
• arranging lifting equipment or shutdown access;
• replacing obsolete or damaged equipment; or
• returning for a separate repair, changeout, or commissioning visit.

Calibration should not be used to conceal a mechanical or electrical problem. Where a fault affects the reliability of the measurement, the report should explain the limitation and the recommended action.

Replacement parts and repair work are arranged through our service and spares team.

What report do you receive?

The report gives the site a record of the visit and the condition of the belt weigher at that time. Depending on the scope, it may include:

• equipment identification and configuration;
• work completed;
• as-found readings;
• as-left readings;
• zero, span, repeatability, and functional results;
• calibration method and test conditions;
• photographs and inspection findings;
• repairs or adjustments completed;
• outstanding issues and recommendations; and
• suggested future service or calibration requirements.

Reports are more useful when they can be compared over time. AIMM keeps equipment details, service history, calibration results, reports, findings, and upcoming requirements together against the relevant asset for customers using the service.

What is the difference between maintenance calibration and legal-for-trade verification?

A routine maintenance calibration is intended to help a site understand and maintain the performance of its weighing equipment for its own operational use. It is not automatically a legal-for-trade approval or certification.

Legal-for-trade, regulated, or customer-specific measurement requirements can involve separate conditions, procedures, approvals, verification, and documentation. If your application involves regulated trade measurement or a contractual accuracy requirement, discuss the requirement with Accurate Industries before booking the work.

How long does a calibration visit take?

The time required depends on the number of weighers, access, site inductions, belt availability, equipment condition, calibration method, repairs, and reporting requirements. A straightforward routine visit may fit within a working day, while faults, cleaning, component replacement, material testing, or restricted access may require additional time.

Accurate Industries will provide a practical time window when the work is scoped with your site.

How often should a belt weigher be calibrated?

The appropriate interval depends on the equipment, application, operating conditions, consequences of measurement error, site requirements, and previous service history. Many operations use a planned calibration schedule and arrange additional checks after significant belt work, roller replacement, relocation, structural changes, or repairs.

The service history in AIMM can help your team track previous visits, upcoming requirements, and changes in results over time.

Does production need to stop?

Some interruption is normally required. The technician may need an empty belt run for the zero check, access under or around the conveyor, isolation for inspection and service, or controlled material flow for a material comparison.

The amount of interruption depends on the equipment and test method. Planning the belt window, isolation support, access, and site resources in advance helps keep the visit efficient.