A practical scale maintenance schedule for Australian sites: daily user checks, quarterly inspections, 6-monthly repeatability tests, annual calibration and trade re-verification.
A sound scale maintenance schedule has four layers: a quick user check before use, a routine inspection at least every three months, a repeatability test every six months, and a full calibration or service every 12 months. Trade scales add a legal layer, because they must be re-verified after any repair or adjustment. At PCS Precision we are NATA accredited and calibrate and service scales on site or in our workshop, so the annual layer and the repairs arrive on a plan, not as a surprise stoppage.
This guide sets out each layer, what it involves, where sites slip, and how to adapt the intervals to your environment. It is written for quality managers, lab supervisors and production teams who need a schedule they can put in a procedure and defend at an audit.
Use this table as a starting template. The manufacturer’s manual always takes priority where it is stricter.
| Frequency | Task | Who does it |
|---|---|---|
| Daily or before use | Check the scale is level, clean and reads zero; place one known weight in the normal range | Operator |
| Per site routine | Clean the pan, platform and surrounds; look for damage, debris, loose parts and cable wear | Operator |
| At least every 3 months | Routine inspection to the manufacturer’s recommendations | Maintenance or a competent person |
| Every 6 months | Repeatability check: 10 measurements of the same mass | Trained staff or a calibration provider |
| Every 12 months (13 months maximum between formal inspections) | Periodic inspection, service and calibration with a traceable certificate | Calibration provider |
| After repair, relocation, damage or adjustment | Calibration check; re-verification if the scale is used for trade | Calibration provider, licensed technician |
The rest of this article explains each row.
A scale rarely fails loudly. It drifts. A platform that reads 20 g high on every pallet or a balance that has lost repeatability will keep producing numbers that look normal. Product giveaway, rejected batches, failed audits and trade penalties are the usual ways the drift is discovered.
A schedule changes the question from “is this scale broken?” to “is this scale still inside its tolerance?” It also gives you the records an auditor asks for. Timing matters on the cost side too: maintenance done too early wastes the remaining life of components, and maintenance done too late lets deterioration spread to other parts and raises the repair bill, as NTI’s maintenance strategy paper puts it.
NATA’s guidance on user checks says a single-point check can be carried out daily or before use. The steps are short:
NATA also notes that when this check is done routinely, the calibration interval for the balance can be reduced to every 12 months (NATA, User checks and maintenance of laboratory balances, January 2018). In practice, the daily check is what lets you defend an annual calibration interval.
Where sites go wrong:
For a ready-made list of daily to annual tasks, see our scale maintenance checklist.
SafeWork NSW’s guide to inspecting and maintaining plant tells businesses to inspect, test, maintain and repair plant in line with the manufacturer’s instructions, or a competent person’s recommendations where those instructions are unavailable or inadequate. It sets routine inspections at the manufacturer’s recommended frequency but at least every three months, and periodic inspections annually, not later than every 13 months. Intervals should be increased in harsh conditions (SafeWork NSW, Guide to inspecting and maintaining plant, 2019).
For a weighing system, a quarterly routine inspection typically covers:
The same guide asks the inspecting person to assess items against acceptance and rejection criteria and to obtain a quantitative measurement where possible. It also asks them to recommend actions such as repairing immediately or within six months, with justification for the period. That is a useful model for your own records: do not log “checked, OK”, log the measurement and the decision.
NATA describes a six-monthly repeatability check: 10 measurements of the same mass (NATA, 2018). Repeatability shows whether the instrument gives the same answer for the same load, and it often degrades before accuracy at zero or at a single point does. A worn loadcell, a sticking mechanical part or a vibrating floor will show up here first.
Compare the spread of your 10 readings against the tolerance your process needs, and keep the results. A widening spread across successive checks is your early warning to book service before the annual date.
NATA says yearly service checks help ensure a balance performs correctly, that adjustments may require a full calibration and a new endorsed report, and that full calibration requires a NATA or equivalent endorsed report, except for approved in-house calibrations (NATA, 2018).
The annual visit is where the instrument is tested against traceable standards across its range, not only at one point. A good annual calibration gives you:
The as-found data is the most valuable part for quality managers. It lets you extend an interval when a scale stays stable year after year, and it tells you when product made since the last check may be affected. We explain how to use it in our guide on defending balance calibration intervals.
For platform and floor scales, the work starts before the technician arrives. Our platform scale calibration pre-checks list what to clear and confirm so the certificate is audit ready on the first visit.
If you buy or sell by weight on the strength of a scale, the schedule is partly set by law. Under business.gov.au’s summary of Australian trade measurement laws, an instrument used for trade must be of an approved type and verified before use by a licensed technician. It must be used correctly (level, and showing zero before use), kept clean and in good working order, and verified after each repair or adjustment. The National Measurement Institute recommends that trade instruments are checked regularly by a licensed technician (business.gov.au).
Three further points shape your schedule:
A worked example: a Class 3 scale with e = 5 g can be wrong by no more than 2.5 g for loads up to 2,500 g (500 e). Your daily check weight should be one you can read against that limit, otherwise you cannot tell a pass from a fail.
For the buying and verification steps before first use, read our guide to legal-for-trade scales in Australia. Food businesses can also see which calibration rules apply to food scales.
The intervals above are minimums for normal conditions. Move to shorter intervals when any of these apply:
SafeWork NSW’s guidance says the same thing in general terms: inspection intervals vary with usage and may need to increase in harsh conditions. Document the reasoning. An auditor will accept a shorter interval with a reason far more readily than an unexplained default.
Do not wait for the calendar if you see any of the following:
Stop using the scale for critical measurements, tag it, and call for a check. For a trade scale, remember that repairs trigger re-verification.
A schedule without records has no value in an audit. Keep, for each instrument:
Labelling the scale with its last and next due dates helps operators and auditors see the status at a glance.
We are NATA accredited and ISO 9001 certified. We calibrate on site or in our workshop, and we support multiple equipment brands regardless of where the equipment was bought. Our service range covers NATA and traceable calibration, preventative maintenance, repairs and trade verification, with 24/7 emergency support. Taking the annual calibration, the repair and the trade verification to one provider means one set of records and one calendar.
If you need loan equipment while an instrument is out of service, we also offer hire equipment. See our calibration and servicing page or our trade measurement page to book. If you are replacing a scale, browse our scales and balances range.
We see the same pattern across manufacturing, laboratory and food sites. The scales that stay in tolerance are the ones with a boring routine: a daily check that someone signs, a quarterly look at the mounts and cables, and an annual calibration booked before the due date, not after the audit.
Our advice is to treat the annual calibration as the anchor and build everything else around it. Keep the as-found results, because they tell you whether your interval is right. Shorten it where your environment is hard on equipment, and let the data justify any extension.
Keep repairs and re-verification in the same plan. When a trade scale is repaired, it needs its mark renewed before it goes back into service, so book both together and avoid the gap.
Our team handles calibration, maintenance, repair and trade verification, on site or in the workshop, so your schedule has one owner and one record.
Kaz
For most business scales, a full calibration every 12 months is the baseline. NATA’s guidance links a 12-month interval to routine daily user checks (NATA). Scales in harsh conditions, with heavy use or with critical products need shorter intervals, and trade scales are generally re-verified every 12 months.
A user check is a quick test by the operator, usually at zero and with one known weight, to confirm the scale is behaving. A calibration tests the instrument across its range against traceable standards and produces a certificate. The user check protects you between calibrations and does not replace them.
Yes. Business.gov.au states that a trade instrument must be verified after each repair or adjustment. The Department of Industry, Science and Resources adds that the previous verification mark must be removed or obliterated before re-verification (DISR). Book the repair and the re-verification together to keep downtime short.
Stop using the scale for anything critical, repeat the check to rule out a handling error, and record the result. If it still fails, tag the scale and arrange a service and calibration. Review product weighed since the last good check, using your as-found data to judge the risk.
Use the same four layers, but set each instrument’s intervals by its use, environment and the criticality of what it weighs. A washdown packing-line scale needs tighter intervals than a lightly used bench balance. Record the reasons in your procedure.
