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Trade Approved Weighbridges in Australia: A Buyer Guide
Quick answer: a trade-approved weighbridge is a truck scale that is allowed to be used where a price or charge depends on weight. In Australia that means the weighbridge design must be approved for trade use and the installed instrument must be checked and certified by a licensed person before it is used, and re-checked regularly. When you compare weighbridge suppliers, ask for the approval details, the load cell certificates and class, the number and capacity of cells, the indicator and software approval, installation scope, certification and ongoing service. Rules are national and can change, so confirm the current requirements with the National Measurement Institute. This guide explains what to ask, how to compare quotes fairly, and the choices that most affect cost and reliability.
What does “trade approved” mean for a weighbridge?
A weighbridge used for trade must meet three requirements together:
- An approved design. The weighbridge model, including platform, load cells and indicator working as a system, is approved for trade use.
- Compliant components. Load cells and electronics meet the standards the approval relies on. Load cells are commonly tested to OIML R60.
- Certification after installation. A licensed person verifies the installed weighbridge using traceable test weights and certifies it, and it is then re-checked at the required interval.
A cell with a certificate is a necessary part, not the whole story. For the full explanation, read legal for trade weighing in Australia.
Who needs a trade-approved weighbridge?
- Quarries, sand and gravel yards selling by the tonne.
- Grain receival points and feed mills paying or charging by weight.
- Scrap and recycling yards.
- Waste facilities charging by weight.
- Transport and logistics companies charging by weight.
If weight is only used internally, with no charge depending on it, a trade approval may not be required, but many operators choose approved equipment anyway so that records stand up in a dispute. If unsure, ask the National Measurement Institute.
Questions to ask every weighbridge supplier
| Topic | Ask | Why it matters |
|---|---|---|
| Approval | Which approved model are you quoting, and what is the approval reference? | Only an approved design can be certified for trade |
| Load cells | What make, model, capacity and class? Are they OIML R60 certified? How many? | Cells carry the load and set the accuracy limit |
| Capacity and size | What platform length, width and capacity, and what axle loads? | Must match your longest and heaviest vehicles |
| Pit or pitless | Is the bridge surface-mounted or in a pit? | Affects drainage, civil works and maintenance |
| Indicator and software | Is the indicator approved? What software prints the tickets? | The indicator is part of the approved system |
| Surge protection | What protection is fitted to cells and cabling? | Lightning is a leading cause of failures |
| Installation | Who does civil works, install, commissioning and certification? | Clarifies scope and responsibility |
| Service | Who services it, how fast, and who holds spare cells? | Downtime stops loadouts |
| Warranty | What is covered and for how long? | Protects against early failure |
Load cells in the quote: what to compare
Two quotes can look similar and differ greatly in the load cells. Compare:
- Type: compression column or double-ended shear beam. See weighbridge load cells.
- Capacity per cell: weighbridge cells carry large margins, because axle loads concentrate on a few cells and vehicles brake and bounce. The Revere ASC2, for example, comes in 30, 40 and 50 tonne capacities.
- Material and sealing: stainless steel, hermetically sealed cells with IP68 or IP69K ratings last longest in wet pits.
- Surge protection: built into the cell or fitted separately.
- Certification and class: OIML R60 with a stated class and number of intervals.
- Matched outputs: cells for one bridge should be matched or trimmed so the load is shared correctly.
See load cell accuracy and quality compared for a side-by-side of real cells.
Pit or pitless?
| Factor | Pit-mounted | Surface (pitless) mounted |
|---|---|---|
| Civil works | Excavation, concrete pit, drainage | Concrete pads and ramps |
| Access for service | Cells beneath the deck; can flood | Cells easier to reach |
| Space | Flat approach, smaller footprint | Needs ramps at each end |
| Cleaning | Debris can collect in the pit | Easier to clean under the deck |
Either can be trade approved. The choice usually depends on your site and drainage.
Comparing quotes fairly
- Put the quotes side by side and compare the approved model, cell make and capacity, number of cells, platform size, surge protection, indicator and software.
- Check what is excluded: civil works, electrical supply, certification fees, freight.
- Ask about lead times, and about the first-year service schedule.
- Ask for references from similar sites.
- Do not decide on price alone. A cheaper bridge with no surge protection may cost more after the first storm season.
Cost drivers (not prices)
We do not quote prices on a guide page, because they vary widely. The main cost drivers are the platform length and capacity, the number and quality of cells, steel or concrete deck, pit civil works, the indicator and software, surge protection, installation access and certification. Send your requirements for a proper quote.
After installation: keeping it compliant
- Arrange certification and re-verification at the required interval.
- Check the zero daily and log it.
- Keep the platform edges, pit and cell areas clean and free of debris.
- Inspect cabling and junction boxes after storms.
- Do not modify the bridge or swap cells for a different type without checking the approval allows it.
- Keep a spare matched cell for critical sites.
Where we fit in
We supply load cells and accessories used in weighbridges, including column and shear beam cells with options for surge protection and sealing. A complete installed, certified weighbridge involves approved design, civil works and certification by qualified providers. If you are a weighbridge builder or you are replacing cells on an existing bridge, send us your details. See weighbridge load cell replacement. Operators in Victoria, Western Australia and other states can read our regional guides for local conditions.
Example: a quarry choosing between two quotes
A quarry receives two quotes for a 18 metre weighbridge. Quote A is cheaper but lists “load cells, 6 off” with no make, class or surge protection, and excludes certification. Quote B names the approved model, lists six stainless steel hermetically sealed compression cells with surge protection, includes commissioning and certification, and a service plan. The quarry asks A to supply the missing details. A cannot, so the quarry selects B, because the missing information is exactly what decides lifetime cost. This is why asking the questions in the table above is worth the time.
Matching the weighbridge to your vehicles
Platform length and capacity should match the longest and heaviest vehicles you expect, not only the average. A common mistake is buying a weighbridge that fits today’s trucks and is too short for tomorrow’s. Think about rigid trucks, semi-trailers and road trains, whether axles are weighed separately or the whole vehicle is weighed at once, and the approach space on your site. A longer deck costs more but avoids weighing a vehicle in two steps. Discuss axle loads with the supplier, because they decide the load on individual cells.
Common mistakes when buying
- Comparing quotes without checking that each names an approved model.
- Ignoring civil works costs, which can be a large share of the total.
- Forgetting drainage, so that water floods the pit or cells.
- Leaving surge protection out to save money.
- Not asking who services the bridge, and how quickly.
- Failing to plan certification and re-verification dates.
The typical project steps
- Define vehicles, loads and approach space.
- Request quotes for approved models with named components.
- Choose a supplier and agree scope, including civil works and certification.
- Prepare the site: foundations, drainage, power and data.
- Install the platform and cells, connect and trim.
- Calibrate with test weights and arrange certification by a licensed person.
- Train operators and set the daily check routine.
- Schedule re-verification and servicing.
Allow time for each step. Civil works and certification are the stages most often underestimated.
A final word on documents
Keep the approval reference, the certification record, the load cell datasheets and serial numbers, the wiring and junction box drawings, and the service history in one folder. When a cell fails or an inspector calls, having these on hand turns a stressful day into a routine one. Update the folder every time anything changes.
How the National Measurement Institute describes it
According to the National Measurement Institute (NMI), the National Measurement Act 1960 requires a weighing instrument used for trade to operate within the permitted error limits and to be pattern approved. Pattern approval covers the design of the instrument, and the approval is issued as a certificate whose number must appear on the equipment. A servicing licensee, a trade measurement inspector or an authorised employee of a servicing licensee tests and verifies instruments used for trade. NMI defines a weighbridge as an instrument with a capacity of 3 tonnes or more with one or more platforms for determining the mass of a vehicle or livestock. A weighbridge that is open for public use for a charge is a public weighbridge, which has its own licensing. The National Trade Measurement Regulations also include a prescribed re-verification period for public weighbridges, so check the current text of the regulations or ask NMI for the period that applies to you. Primary sources: NMI’s pages on verifying weighing instruments for trade and weighbridges used for trade.
Frequently asked questions
How do I know a weighbridge is approved?
Ask for the approval reference for the model being quoted and confirm it with the National Measurement Institute if needed.
Can I use any load cell in an approved weighbridge?
No. The approval specifies the type of components. Do not substitute without checking.
How often must it be re-verified?
Intervals depend on the instrument and the rules, so confirm with the regulator or your licensed provider.
Can you supply a complete weighbridge?
Tell us what you need through the contact page, and we will explain what we can supply and who would install and certify it.
What is the biggest cause of weighbridge failure?
Water and lightning, followed by mechanical binding and debris. Good drainage and surge protection prevent most of it.
Next steps
Read weighing and pressure sensing for mining and our supplier checklist.
