The MID has a section dedicated to Rail Weighbridges: The Measuring Instruments (Automatic Rail-weighbridges) Regulations 2006. However, there is no such section for road weighbridges.
Requirements for weighbridges
Public road vehicle weighbridges
There are legal requirements for public weighbridges that do not apply to private ones. After checking on installation, the Trading Standards Officer (TSO) will check (reprove) the weighbridge every six months and give it a stamp. This stamp will be obliterated by the TSO if it fails a test, but will be reinstated if it passes. Any weighbridge certified by the TSO is acceptable to us.
Private road vehicle weighbridges
As above, the TSO will stamp the weighbridge on installation. However, from then on it is up to the trade to have the weighbridge re-proved - the TSO will not test the weighbridge as a matter of course and obliterate the stamp if it is found inaccurate. The weighbridge is only acceptable therefore if it has been reproved at least annually.
Accuracy classes of weighbridges
As with flow meters, there will be accuracy classes of weighbridge, and these are:
|Accuracy Class||Maximum permissible error expressed as a percentage of mass of a single wagon or total train as appropriate|
|0.2||+ or - 0.2%|
|0.5||+ or - 0.5%|
|1||+ or - 1%|
|2||+ or - 2%|