A trade measurement inspector visits a deli, a produce store or a quarry weighbridge and marks an instrument non-compliant. The trader rings their scale company. The question at both ends of the phone is the same: once it is fixed, does it need verifying again before it can weigh for trade?
National Measurement Institute (NMI) guidance answers that with two lists, one of problems that do not need re-verification after repair and one of problems that do. This article sets them out for weighing instruments, with a short note on fuel dispensers. It summarises NMI guidance and is not legal advice; check the current NMI pages, or ask NMI, about a specific case.
The principle
For a weighing instrument to be suitable for trade use, NMI says the National Measurement Act 1960 requires it to be pattern approved and to operate within the limits of error permitted under the regulations. Whether an instrument needs verifying after adjustment or repair depends on whether the problem could affect its measuring performance.
Problems that don’t need re-verifying
NMI says not to re-verify a weighing instrument when an inspector has marked it non-compliant only because of:
- environmental conditions outside those its certificate of approval allows
- a faulty extra indicator or printer
- faulty keypad buttons
- a display with missing segments
- missing details on the display, such as missing decals
- an incorrect, incomplete, illegible or missing data plate
- an unstable installation, or an instrument that is not securely fixed
- a faulty level bubble
- a faulty zero indicating device
- missing or broken levelling feet
- weighbridge approaches that do not comply.
After those repairs, the trader can use the instrument for trade.
Problems that do need re-verifying
Re-verification is needed when the problems include:
- faults in electronic circuit boards
- an unreadable display
- the wrong software version
- price computing errors
- accuracy, eccentricity or repeatability errors beyond the maximum permissible error (MPE)
- inaccurate zero and tare setting
- discrimination or sensitivity outside what is permitted
- a faulty zeroing device
- zero shift beyond the MPE
- belt weighers and automatic totalising hopper weighers running outside their flow rate range.
When you re-verify, remove or obliterate the previous verification mark first.
Modified load receptors
Scoops, rollers or a replacement platform change an instrument’s load receptor. NMI still treats a non-automatic weighing instrument with a modified load receptor as being of an approved pattern only if a list of conditions is met. They include that the modification does not affect measuring performance, that the instrument still passes its test procedure for accuracy, repeatability and eccentricity, and that it is re-verified after the modification.
Keep it level
Non-automatic weighing instruments must be level when they are tested for verification. If the level bubble is not clearly visible to the user, NMI says a notice must show where it is. NMI also asks verifiers to explain to traders that an instrument that is not level and gives inaccurate measurements may be an offence, and that their staff should know how to check it.
Fuel dispensers
NMI publishes a similar pair of lists for fuel dispensers. A faulty hose, nozzle, motor or pump, for example, does not call for re-verification after repair, while meter creep, a faulty non-return valve, leaks in pipe work downstream of the meter or errors beyond the MPE do. Check NMI’s fuel dispenser page for the full lists. Fuel retailers can read how OpsChase handles site repairs for service stations.
For traders
If an inspector has marked your scale or weighbridge non-compliant, your scale company can tell you which list the problem falls in. Servicing licensees and their nominated verifiers test and verify instruments used for trade, and NMI publishes a list of servicing licensees, by licence subclass, that have agreed to be listed.
How OpsChase records repairs and re-verifications
OpsChase for trade measurement verifiers is built for Australian trade verification rather than generic scale calibration software. Every customer instrument has one record: make, model, serial, approval number, capacity and full verification history. A repair job and the re-verification that follows sit on the same instrument, pass, fail or non-verification is recorded with a reason, and the Form 6 export picks up the new verification.
Verifiers follow the test steps for that instrument class on a phone or tablet, with results flagged against the MPE as they are entered, and the mark is built for them. Customers get a branded certificate, which many still call a scale or weighbridge calibration certificate, and a reminder when their next check is due. OpsChase is independent software, and it is not made or endorsed by NMI.
Where to start
Bring across your customer sites and instruments, then run your next repair call-out and re-verification through OpsChase. Read the form mistakes that send a Form 6 back, check pricing or book a demo.