WOULD you really notice if your beer is a tad too much froth and not enough of the good stuff?

Actually, I do know people who would thrash a bartender within an inch of his life for this particular sin, but generally it goes unnoticed in most watering holes.

Which is why it is mind boggling to see just how much consumers are being cheated out of every year in just about every retail industry dealing in weights and measures.

According to a recent report, hundreds of millions of pounds are lost because of shops and businesses dealing a dodgy card.

In British pubs alone, customers are being fiddled out of 200 million pints of beer and cider, netting the industry an extra £130m.

And because petrol changes in volume according to the temperature, motorists and garages are sometimes paying way over the odds for their fuel, the National Audit Office report said.

Weighbridges

In terms of faulty or incorrectly set scales and other equipment used to weigh goods, Trading Standards officers found that in 2000-01, five per cent of the two million scales in use were inaccurate.

For instance, a fifth of weighbridges used to weigh lorry loads in Hampshire were found to be inaccurate, potentially costing the drivers and customers who went on to buy the goods £250m.

There were also cases of outright deceit, such as that involving a Gainsborough coal merchant who drilled a hole in a 25kg counterweight to trick customers out of 1.5kg on each purchase. He was prosecuted and fined more than £2,000.

The report, presented to Parliament by NAO head Sir John Bourn, said every week, around £1bn-worth of retail goods were sold in the UK on the basis of the measurement of their quantity.

''It is therefore vital that all trade measurement is accurate, fair and legal to buyer and seller," he said.

''Consumers often cannot readily confirm that the quantity they have purchased is the actual amount received.

''For example, when buying petrol we have to rely on the accuracy of the display on the petrol pump and similarly, when buying spirits in a pub, the purchaser needs to rely on the fact that the spirit measuring instrument will provide the right amount.''

The report highlighted the problem of petrol stations being delivered less fuel than they had paid oil companies for, because it cools when it is stored at the forecourt.

This was costing garages and motorists up to £80m a year, it warned.

Failing to provide full liquid measures of draught beer and cider allowed licensees to sell an estimated 200m more pints a year than they bought in, at an estimated value of about £130m at wholesale prices.

Sir John said the report showed the need for the Department of Trade and Industry to have better information about the level of protection for consumers.

"The department should press ahead quickly with its plans to modernise legislation, as well as improving its information about local enforcement of that legislation," he said.

"This needs to be done if the department is to be effective in promoting appropriate standards of trading across the country.''