Maintenance on the Weighbridge

The most prominent feature of the weighbridge is the steel or concrete platform on which vehicles drive on and off. For electronic versions, the platform rests on a set of load-cells which are wired to a “brain box”, computer or digital readout unit and a printer. In the case of the mechanical version, the platform is suspended on systems of pivots and levers in a pit which through linkages are connected to a calibrated beam with counterbalance weights with mechanisms to a printer and dial system. The installation, calibration and certification of a weighbridge for trading must be affected in accordance with the local regulations that may be in force. It is the duty of the operator to see to it that the weighbridge under his control is in good working order at all times by carrying out regular basic weighing accuracy tests and maintenance.

The weighbridge must be serviced before commencement of the grain reception season. Regular cleaning checks and tests must be carried out during the course of the season. The weighbridge should be serviced every three months by the manufacturer’s representative or a reputable and approved firm. The fundamentals of servicing the weighbridge include:

• Ensure that the weighbridge is always clean and tidy. Remove any grains, mud, water, debris, rat and rat nests.
• Ensure that all drains are opened and drain freely.
• Check and ensure free movement of the platform on the knife edges.
• Check and ensure that the weighbridge dial or readout is zero before using.
• Carry out regular tests to confirm accuracy and consistency of weighing. Simple tests such as placing a mass of 50 to 100kg test weights on the four corners and at the centre of the platform successively and noting if all the five readings tally. Also determine the mass of about 10 bags of grain from the bagging plant on the weighbridge and noting if they tally. A further simple test is to determine the mass of two short trucks separately and then jointly and compare the masses. If, from the tests, discrepancies in weights are observed, the manufacturer’s representative or the approved service company must be called to check, calibrate and service the weighbridge.
• Printers should be serviced as appropriate.
• The weighbridge should be checked once every 2 years, and certified by the relevant government agency. Since weighbridge constitutes the main point of disputes and cause for dissatisfaction between agents and buyers, as the main reason for short weights and difference between weights envisaged and received, it is important that the weighbridge facility is properly operated and maintained all the time.