Truck Scales / Weighbridges

Over the last 45+ years, Thames Side has specifically developed load cells and instrumentation/electronics for accurate, commercial (trade) weighing of vehicles driving onto truck scales/weighbridges.

T34 and T35 Compression Rocker Column Load Cells

T34

T35

Digital T34D Load Cell

An even better solution is to use a digital load cell. The Model T34D digital compression rocker column load cell provides the following advantages and benefits over the standard (analogue) T34 load cell:

• Higher resolution (up to 1,000,000 steps from zero to full scale) - resuting in a more precise truck scale 

• Intelligent, error-free compensation for each individual load cell, with simpler and faster corner adjustment - which saves time during troubleshooting

• Open protocol - we can provide the communications protocol on request

• Simpler and faster maintenance with continuous, individual self-diagnosis

• Remote diagnostics via modem using direct PC connection (with the Matrix 2 weight controller) - therefore the site does not have to be visited to determine if there is a load cell fault

• Greater EMC protection against interference (digital signal transmission) - meaning less signal error

• Direct PC connection via RS485 bus and RS232 converter, up to 1200 metres away - meaning that the 'control room' or 'booth' does not need to be very near to the truck scale

• Internal signal filtering for each load cell, resulting in a more stable output

System Calibration

Many of our local weighing system Partners, who are experts in their field, will be able to supply truck scale calibration services if you wish to have your system calibrated or certified. Please visit our Partner Network page to contact your local Thames Side partner.

Background Information

A truck scale, or weighbridge, is essentially a large platform scale that is used to weigh an entire vehicle, for the purposes of reading the weight of the vehicle before it is filled with material, or after it is emptied. Often a truck scale is a legal-for-trade approved scale used to issue tickets that will be used for commercial (invoicing) purposes. Commercial truck scales must be calibrated by a certified company, using verified and traceable measuring equipment. Therefore truck scale load cells usually need to be approved according to an organisation such as OIML.

For permanent or semi-permanent truck scales/weighbridges the weight readings are usually recorded with equipment located in a nearby hut or office. Most weighbridges are now linked to a PC that runs truck scale software - this controls barriers, traffic lights, RFID card readers, ANPR systems (automatic license plate reading systems), enables the printing of tickets and provides reporting features.

There are various different types of truck scale around the world, with each region tending to favour a particular type. The most common 3 types have from 4-16 load cells and of maximum length 18 or 36 metres, as follows:

• Traditional Fabricated Steel; high or low profile design

• Pre Stressed, Pre Cast Concrete; low profile design; modular

• Poured on Site Concrete; single span or modular steel frame with concrete infill

Application Challenges

Typical problems encountered with truck scale/weighbridges:

• Pit mounted truck scales/weighbridges can be affected by rain, flooding, dirt and rodents etc. Installation of a truck scale/weighbridge near lowered areas of road or ground should be avoided - this prevents rainwater or floodwater running down into the pit area, which would cause the load cells to be submerged.

• Additionally, as for all multi-cell platform scales a truck scale/weighbridge system must output the same value no matter where the weight is positioned on the scale.  For example, if a truck carrying liquid drives onto the scale and stops suddenly, the centre of gravity of the truck will be moving around for some time. Waiting for the centre of gravity to stabilise is not an option; productivity would be seriously compromised in this situation. If the sensitivity values of the load cells were all significantly different, the weight reading would change depending on where the centre of gravity of the truck was located.  The solution: choose T34 or T35 load cells that have been pre-corner adjustment optimised during their manufacture and calibrated in mV/V/Ohm to provide matched current outputs. This allows for much faster commissioning of the truck scale/weighbridge because minimal (or no) corner adjustment is required. Thames Side's Model T34 and T35 compression rocker column load cells are pre-corner adjustment optimised @ ±0.05% by calibration in mV/V/Ohm.

More Information

Contact Thames Side now to discuss your requirements for load cells, weight controllers and electronic accessories for use in truck scales/weighbridges.

We have the experience to provide expert guidance.