Your weightometer reads 4,180 tonnes for the shift and nobody questions it — until month-end reconciliation shows the plant shipped more than the belt scale said it moved. A belt scale that quietly drifts half a percent doesn't trip an alarm; it just reports the wrong number on every tonne, and that error flows straight into production figures, royalty calculations and your metallurgical balance. Good weightometer calibration isn't a once-a-year visit from a scale tech — it's a managed routine of scheduled checks, standardised procedures and a certificate trail you can defend at audit. Book a demo to see calibration tracked, not chased.
Schedule zero, span and material checks, standardise every calibration routine, and keep a traceable certificate trail for every belt scale in the plant — so your tonnage data holds up at audit.
A weightometer is one of the few instruments in a processing plant whose errors are invisible and expensive at the same time. It never stops reporting, so it looks like it's working even when it's drifting. This guide covers what belt scale drift actually costs, the three calibration checks that catch it, and how to run weightometer calibration as a managed, audit-ready routine instead of a scramble before the next reconciliation. Book a demo to see it managed end to end.
Why a drifting weightometer costs more than you thinka small percentage error, multiplied by every tonne
The danger with belt scale drift is scale. A fraction of a percent sounds like nothing — until you multiply it by the throughput of a primary conveyor over a month. The error doesn't stay a measurement problem; it becomes a money problem.
And drift is normal, not exceptional. Material buildup on the weigh frame is the biggest culprit — as little as a few pounds of caked ore can add several tonnes per hour to the totals. Ice, a debris-fouled speed sensor and a shifted idler all push the number the same way. See how HVI's inspection management catches the physical causes before they reach the reading. Book a demo to see belt scale checks scheduled automatically.
The three weightometer calibration checkswhat each one proves, and how often it runs
Weightometer calibration isn't a single event — it's three checks at three frequencies, each catching a different kind of error. Managed together, they keep a belt scale honest; run in isolation or forgotten, they don't.
Run the belt empty and confirm it reads nothing. Repeatable results mean the frame is clean and the zero is stable; a wandering zero is your first warning of buildup or ice.
Apply a known static weight (or weight chain) and confirm the scale reads it correctly, comparing against previous span results. A span that's drifting against its own history signals a certified calibration is due.
Weigh material passing the belt against a certified truck or rail scale — the gold-standard check, and the one Legal-for-Trade scales require. It's the certificate auditors want to see, so its result and date have to be traceable.
The daily and periodic checks are plant-crew tasks; the material test brings in a certified technician. The constant across all three is documentation — a check nobody recorded is a check that didn't happen as far as an auditor is concerned. Book a demo to see all three checks on one schedule.
Weightometer calibration checklistthe field routine, standardised so every check is done the same way
The fastest way to make calibration reliable is to stop leaving it to memory. This is the routine a plant crew should run — build it once as an audit checklist in HVI and every technician follows the same steps, with a timestamped record at the end.
Run this way, every calibration is identical and self-documenting. Start free and build this as a reusable audit checklist.
The calibration certificate trail auditors wantfrom loose PDFs in an inbox to a traceable record per scale
When an auditor, a royalty reviewer or a customer queries your tonnage, the question is always the same: prove the scale was accurate. Loose certificates scattered across inboxes and a filing cabinet don't survive that. A record that lives against each belt scale does.
- Certificate PDF sits in one person's email
- No one's sure which was the last valid material test
- Zero and span checks live in a paper logbook, if at all
- Audit means a week of digging and hoping
- Every certificate attached to the belt scale it belongs to
- Current material-test validity and expiry visible at a glance
- Full zero / span / material history, timestamped and searchable
- Audit means pulling up the record and moving on
That's the maintenance-records side of calibration management — the part the scale technician doesn't do for you. Explore how HVI keeps maintenance records against every asset, and tie your fixed-plant calibration into the same system as the rest of your mining plant maintenance. Book a demo to see the certificate trail per scale.
A plant maintenance tech on belt scale calibrationwhy managing it beat trusting the number
We got burned on a reconciliation once — the weightometer on the primary conveyor had been reading high for weeks and nobody caught it because the daily zeros were being eyeballed, not logged. Turned out to be buildup on the frame. Now the zero and span checks are a fixed routine with a recorded result, and the material test cert is tracked to its expiry. The difference is I can answer "when was this scale last proven accurate" in about ten seconds instead of a day of hunting for a PDF.
Weightometer calibration FAQswhat plant maintenance teams ask most
How often should a weightometer be calibrated?
Run a zero check daily, a span check periodically against its own history, and a certified material test on a scheduled interval set by your site and local weights-and-measures requirements. The daily and span checks are crew tasks; the material test brings in a certified technician.
What's the difference between zero, span and material calibration?
Zero confirms the empty belt reads nothing, span confirms a known static weight reads correctly, and the material test weighs actual material against a certified scale. Material comparison is the most accurate and the one Legal-for-Trade scales require.
What causes belt scale drift?
Material buildup on the weigh frame is the biggest cause — even a few pounds can add tonnes per hour to the totals. Ice, a debris-fouled speed sensor and idler condition around the frame all push the reading too, which is why a clean frame and a logged zero come first.
Does HVI calibrate the weightometer?
No — the physical calibration stays with your crew and certified scale technician. HVI manages the process around it: scheduling every check, standardising the routine as an audit checklist, and holding the certificate trail so accuracy is always provable.
Why do calibration records matter for audits?
Because tonnage data feeds production reporting and royalties, you have to prove each scale was accurate for the period in question. A searchable record of every zero, span and material test against each scale turns an audit from a week of digging into a quick lookup.
Run weightometer calibration as a managed routine
Stop finding belt scale drift at month-end. Let HVI schedule the zero, span and material checks, standardise the routine your crew follows, and keep the certificate trail that makes your tonnage data defensible.
- Scheduled zero, span & material checks
- Standardised audit-checklist routines
- Certificate trail per belt scale
- Searchable history for audit
