Truck weighbridge lanes with a barrier and lane signs at a freight entrance

Weighing · Computer Vision

Automated Weighbridge with Number Plate Recognition

An automated weighbridge identifies every truck by its number plate, weighs it in and out without a clerk writing tickets, photographs the load, and sends the net weight to your accounts or ERP. It speeds up the gate, removes manual errors, and closes the gaps that weighbridge fraud depends on.

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What it does: Reads the plate, weighs in and out, matches gross and tare, calculates net weight, prints or sends the ticket.
Where it fits: Tea factory leaf intake, cement and aggregate dispatch, quarries, paddy and grain stores, scrap yards, factory gates.
What it stops: Wrong or swapped vehicle numbers, partial weighing, tare tricks, edited tickets and queues at the gate.
What you get: A ticket per trip with plate, weights, time and photos, exported to your accounting or ERP system.

Definition

What is an automated weighbridge?

An automated weighbridge is a truck scale connected to cameras, barriers and software so that weighing happens with little or no manual input. Automatic number plate recognition (ANPR) identifies the vehicle, the weighbridge indicator supplies the weight, and the software links the inbound and outbound weighings into one transaction with a net weight.

Cameras also photograph the truck, the load and the plate at each weighing. That record settles disputes with suppliers and customers, and shows if a vehicle was not fully on the platform or if the wrong truck was weighed.

The weighbridge itself stays the legal measuring instrument. In Sri Lanka, weighbridges used for trade are verified by the Measurement Units, Standards and Services Department, and non-automatic weighing instruments are covered internationally by OIML R 76. Automation reads the verified indicator; it does not change the measurement.

Freshly delivered green tea leaf spread in a withering trough inside a tea factory — Green leaf at a tea factory. Every lorry load is weighed on arrival, which makes leaf intake one of the busiest weighbridge operations in Sri Lanka.

The problem

Where manual weighbridges lose money

Vehicle numbers are typed by hand, so mistakes and swaps go unnoticed.
A truck partly off the platform, or a driver standing on it, changes the weight.
Tare weights can be reused or manipulated between trips.
Paper tickets are re-keyed into accounts, with errors and delays.
Queues form at peak intake times, such as green leaf arrival at a tea factory.

How it works

How an automated weighbridge works, step by step

STEP 1
Identify the vehicle
An ANPR camera reads the number plate as the truck approaches. Known vehicles and suppliers are matched automatically; an RFID tag or driver card can be added.
STEP 2
Check the position
Cameras and position sensors confirm the vehicle is fully on the platform before the weight is accepted.
STEP 3
Capture the weight
The stable weight is read from the weighbridge indicator, with photos of the truck, load and plate stored against it.
STEP 4
Match in and out
On the second weighing the software pairs gross and tare for the same plate, calculates net weight and applies any deductions you set.
STEP 5
Ticket and export
A ticket is printed or sent by SMS or email, the barrier opens, and the transaction goes to your accounting or ERP system.

The technology

Methods that make it reliable

Automatic number plate recognition

A camera with infrared illumination captures the plate day and night, and OCR tuned for Sri Lankan plate formats reads the province code, letters and numbers.

Weighbridge indicator integration

The weight is read digitally from the indicator, usually over a serial or network connection, so nobody types it. Our own load cell and weighing electronics are built in house, and we can work with an existing weighbridge or supply the electronics.

Platform position checking

Cameras and photoelectric sensors at both ends of the platform confirm all axles are on the deck and nobody is standing on it before the weight is recorded.

Load photography

Overhead and side cameras photograph the load at each weighing, giving a visual record of what came in or went out.

Transaction software

Inbound and outbound weighings are matched by plate, net weight is calculated, and each trip is exported to accounts or ERP with its photos.

Capabilities

What it can check

Number plate read and matched
Vehicle fully on the platform
Stable weight captured
Gross and tare paired automatically
Net weight and deductions calculated
Photos of truck, load and plate
Ticket printed or sent
Barrier control
Export to accounts or ERP
Exception alerts for unknown vehicles

Industries

Where it is used

Tea factories, green leaf intakeCement and aggregatesQuarries and miningPaddy, grain and feed storesScrap and recyclingSugar and agricultural processingFactory and estate gates

Sample projects

How a project is scoped

Two example project scopes showing how the station, the checks and the outputs are defined. Every plant is different, so the final configuration is confirmed after a feasibility study on your own parts.

Example scope · Tea factory

Green leaf intake weighbridge with ANPR

The situation: A tea factory receives leaf lorries from many collection routes in a short evening window, and weighs them with a clerk writing tickets by hand.

Station: ANPR camera, platform position sensors and load cameras on the existing weighbridge
Process: Lorry identified by plate, weighed in full, weighed out empty, net leaf weight per route
Output: Ticket per trip with photos, daily intake by route and supplier
Extra: Data passed to the leaf accounting system without re-keying

Example scope · Quarry

Unmanned dispatch weighbridge for aggregates

The situation: A quarry dispatches aggregate trucks all day and loses time and revenue to queues, hand-written tickets and tare disputes.

Station: ANPR at entry and exit, barriers, ticket kiosk and load cameras
Process: Stored tare per vehicle checked against the live tare, gross weighed on exit
Output: Printed ticket and invoice data per load, barrier opens automatically
Extra: Alerts for unknown vehicles or tare out of range

What is in the system

Typical components

ANPR camera with infrared illumination
Overview and load cameras
Weighbridge indicator interface or our own weighing electronics
Platform position sensors
Boom barriers and traffic lights
Ticket printer or kiosk
Industrial PC and weighbridge software

Cameras and lenses, supplied locally

Industrial cameras, lenses, line-scan cameras and code readers are available through our machine vision catalog, quoted with delivery to Sri Lanka. We select the hardware for your application during the feasibility study.

Browse the hardware catalog

How we work

Proven on your parts before you commit

Every product, surface and line behaves differently under a camera, so every project starts with evidence from your own material.

PHASE 1
Discovery
A site visit to understand your product, line speed, quality criteria and where the check should sit.
PHASE 2
Feasibility study
We image your good and defective samples and show what the system can reliably detect. This is the go or no-go.
PHASE 3
Pilot station
One station on one line, running beside your inspectors until results match and your team trusts them.
PHASE 4
Rollout and support
More lines, integration with your PLC and systems, and local support from our Sri Lankan engineering team.

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All applications

Every machine vision application we design and build, in one place.

FAQ

Automated Weighbridge & ANPR: common questions

Can you automate our existing weighbridge?

In most cases, yes. If the indicator has a serial or network output, we read the weight from it and add cameras, sensors, barriers and software around the existing platform. If the electronics are old or faulty, we can supply new weighing electronics, which we build in house.

Does automation affect legal verification of the weighbridge?

The weighbridge remains the legal measuring instrument and still needs verification by the Measurement Units, Standards and Services Department for trade use. Automation reads the verified weight; it does not alter the measurement.

Can ANPR read Sri Lankan number plates?

Yes. The recognition is set up for Sri Lankan plate formats, including the province code. Dirty, damaged or non-standard plates can fail, so the system flags any read it is not sure of for a quick manual check, and an RFID tag can be used as a backup for regular vehicles.

How does it prevent weighbridge fraud?

It removes typed vehicle numbers and weights, checks that the vehicle is fully on the platform, photographs every weighing, pairs gross and tare automatically by plate, and keeps a tamper-evident log. Most common frauds rely on one of those steps being manual.

Can it work for tea factory leaf intake?

Yes. Leaf lorries can be identified by plate or tag, weighed in and out, and net leaf weight recorded per route or supplier, with photos of each load. The data can feed your leaf accounting so nothing is re-keyed.

Does it connect to our ERP or accounting system?

Yes. Each transaction can be exported to your accounting or ERP system as a data file or through an integration, so weights flow straight into invoicing or supplier payments.

Send us a few sample parts

Tell us what you need to check and share some good and faulty samples. We will show you what a camera can reliably see before you commit to anything.

Get in touch info@ceroxengineering.com

Photographs show representative plants and equipment, not Cerox installations or client sites. Diagrams by Cerox Engineering. Photo credits, via Wikimedia Commons: Dedicated lane for truck weighbridges by Fumikas Sagisavas, CC0; Green tea leaf in a withering trough by shankar s., CC BY 2.0.