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Guidance on public weighbridge operator certification

Qualifications required

Operators of public weighing equipment have responsibilities to ensure that they can perform their duties competently and honestly. Further, no one may operate public weighing equipment unless he/she holds a certificate from a chief trading standards officer.

Applicants for a certificate will be tested via a written or verbal test and practically by an inspector and will be required to show that they can:

  • operate the weighbridge satisfactorily
  • complete any weighbridge tickets and associated documentation satisfactorily
  • understand basic terms associated with the operation of a weighbridge
  • understand their duties as a weighbridge operator
  • understand potential frauds which may unknowingly be assisted by a weighbridge operator
  • understand how the accuracy of the weighbridge may be affected
  • perform simple arithmetic (use of a calculator is permitted).

Before applying for a test, please ensure that you have received sufficient training in the operation of the equipment and that you have completed the application form. This document will be required by the inspector when he/she tests you.

It is the policy of this authority to limit the scope of any certificate to the weighbridge that the operator will be expected to use. Should the weighbridge be replaced or changed a new certificate will be required.

Legal requirements

Weights and Measures Act 1985

Section 18

Operators of public weighing equipment must hold a certificate of competence from a chief inspector of weights and measures.

Section 20

  1. Must carry out a weighing on demand unless they have reasonable cause not to do so.
  2. Must carry out the weighing fairly.
  3. Must give to the person requiring the weighing a written statement of the weight found.
  4. Must make a record detailing:
    1. time
    2. date
    3. particulars to identify the vehicle
    4. the load on the vehicle.
  5. Must not make a false record or give a false statement.
  6. Must not commit any fraud.
  7. Persons bringing an item to be weighed must, if requested, give his name and address to the operator.
  8. Records of weighings must be retained for two years.
  9. Record must not be destroyed or defaced within two years.

Regulations made under the above Act prohibit the double weighing of vehicles for trade purposes (such as axle weighing).

Good weighing practice

  1. Regular checks should be made to ensure that there is clearance between the plate and its surrounding frame. If the weighing machine operates using a lever bottom work, the plate should swing freely endways.
  2. Regular checks should be made to ensure that the weighbridge is properly balanced when unloaded and the indicator shows zero. The weighbridge operator must know how to balance the weighing machine.
  3. The balance of a weighbridge will be affected by the accumulation of dirt etc. on or around the plate. This should be regularly cleaned to avoid any excessive build-up. Beneath the plate, levers or load cells may be affected by the build-up of dirt (sand) and should be cleared as necessary. If your weighbridge is prone to such contamination a regular maintenance programme should be implemented. In a pit mounted weighbridge, balance and accuracy may be affected by a high water level in the pit which ‘floats’ the levers or the bottom work. In such circumstances pumping facilities should be available and the weighbridge operator will be expected to know how to use it. The most common cause of ‘balance’ error is due to rain on the plate. During periods of rain the balance should be checked and adjusted more frequently and again as the plate dries.

Weighing procedures

  1. It is advisable to weigh all vehicles without passengers or driver. If this is not possible or if the personnel refuse to leave the vehicle a note should be made to this effect with details of the number of persons on the vehicle. This note should be made on the ticket and on any other record. This information is required because certain persons may wish to increase the GROSS weight of the load by addition of passengers and if and when the tare weight is taken without passengers the weight of the load appears heavier. Weighbridge operators should take special care whilst passengers are on or in the vicinity of the plate.
  2. Where practical the weighbridge operator should check the load for himself and if this is not possible the ticket should indicate the load as stated by the driver. Weighbridge operators should be aware that persons bringing loads to be weighed may conceal heavy items amongst the stated load. This heavy article can then be discarded and the goods delivered to a purchaser. For example, Concrete blocks with scrap metal. The load is identified as scrap metal and following weighing the concrete is discarded and the scrap metal sold at the higher weight. Therefore the weighbridge ticket would be properly completed as ‘scrap metal/concrete’.
  3. The operator should always check any vehicle registration number for himself rather than rely on the driver.
  4. The weighbridge operator should have a clear view of the plate and ensure the vehicle being weighed is positioned on the plate. Weighbridge operators should be aware that persons requiring a weighing may deliberately leave a wheel over the edge of the plate to reduce the weight shown. This is either done to reduce the tare weight (and therefore increase the apparent weight of the load or to appear below the permitted legal weights for overloading purpose.
  5. It is illegal to undertake a double weighing where that weighing will be used for a trade transaction (for example, a load of hay for sale elsewhere).

Drivers sometimes require a weighing to ensure they are not overloaded on individual axles

It is permissible to undertake weighings of individual axles but the ticket and records should clearly indicate what type of weighing was carried out and which axles were weighed. The ticket should be endorsed – “Weights found are not for trade purpose”.

Weighbridge ticket

A weighbridge operator must give a statement in writing of the weight found to the person demanding the weighing or to his agent (this may be an arrangement made formally or informally but the statement should always go with the vehicle).

They must enter the weight found in the GROSS or TARE box on the weighbridge ticket as appropriate.

If the ticket is to be issued then the weighbridge operator must enter NOT WEIGHED or draw lines through the spaces provided for other entries. Operators must not enter in the tare box a weight stated by the driver, as only weights determined by the weighbridge operator should be inserted.

If the driver intends to return after loading for a second weighing of the same vehicle to be recorded on the same ticket, the ticket should be retained until the second weighing is complete. A weighbridge operator should never give out a ticket that has any blank spaces.

They must complete the other particulars required on the ticket.

Note: Often when using an electronic headwork with ticket printer the information is fully or partly transferred onto the ticket. However, if this fails full records must still be kept and any calculations worked out accurately.


The weighbridge operator must ensure that a record of each weighing is made.

These records must be kept for at least 2 years. If the duplicate of the weighbridge ticket is the only record of the weighing, it must also state:

  • the time of weighing
  • the registration number of the vehicle (if applicable)
  • the weight found
  • the date
  • the nature of the load.

If a weighbridge operator suspects any irregularities in a request for, or the use of, public weighbridge weighings, their local Trading Standards office should be informed.

The maximum penalty for fraud in connection with a public weighing is a fine of £5,000 or six months imprisonment, or both. The maximum penalty for recording a false weight is a fine of £5,000.

Road Traffic Act (vehicle overloading)

Whilst not strictly a matter for a certificated weighbridge operator we would expect an operator to have a basic knowledge of vehicle weights. If, having weighed a vehicle, a weighbridge operator suspects the weights to be in excess of
that permitted for the vehicle on the highway they should draw the driver’s attention to the weight record. Further, the ticket should be marked ‘vehicle possibly overloaded’.

A weighbridge operator does not have authority to:

  1. Withhold the weighbridge ticket.
  2. Prevent the vehicle leaving.

Common terms associated with weighbridges

  • Balance: When the weighbridge is unloaded the indication shows zero.
  • Gross weight: This is the weight of the vehicle fully laden, and is an indication of the total weight of everything on the bridge.
  • GVW: Gross vehicle weight.
  • Tare weight: This is the weight of the unladen vehicle, i.e. the weight you will use to calculate the vehicle’s load.
  • Net weight: Gross weight less tare weight i.e. the weight of the load.
  • Train weight: Similar to gross weight and refers to the all-up weight of an articulated vehicle (tractor and trailer). On weighbridge documentation it will still be referred to as gross weight.
  • GTW: Gross train weight.
  • Headwork: The part of the machine which incorporates the weight indications.
  • Bottom work: The levers and/or load cells below the plate.
  • Plate/Platform: The part of the machine on which the load to be weighed is placed.
  • Double weighing: The weighing of a load or vehicle in two or more stages, for example, where an articulated vehicle cannot fit onto the plate its weight is calculated from the sum of the front and rear sets of axle weights.
  • Axle weighings: The weighing of individual axles or groups of axles to determine the load placed upon them.
  • Draw bar unit: A rigid vehicle towing by means of a bar a self-supporting trailer.
  • Permitted GVW and Permitted GTW: The legal maximum weight permitted on the road.

Self-assessment sheet

If you are unable to answer the following questions we would recommend you reread the booklet and discuss the matter with your supervisor.

  1. In what circumstances can you refuse to undertake a public weighing?
  2. What do you understand by the following terms? Gross weight/Net weight/Balance/Tare/Double weighing.
  3. What checks should you make prior to making a weighing?
  4. What could cause an inaccurate weighing being recorded?
  5. What offences can you commit under section 20 of the Weights & Measures Act 1985?
  6. How long should you keep records/copy tickets of weighings for?
  7. What information should be recorded on a record/ticket?
  8. Where are the records copy tickets stored within this business?
  9. Should you weigh a vehicle with or without the driver/passengers?
  10. Why should you have a clear view of the plate?
  11. How long have you been operating this particular weighbridge?

In preparing for your test please expect additional questions to those detailed above as these are for your benefit to judge your readiness.