Metrication in the United Kingdom

"I am led to the conslusion that comprehensive universal metrication is a bit of nonsense... There is a gap between the millimetre and the metre, there is no centimetre... The kilo is too heavy for the housewife to carry and we know that in France and Denmark they use the old system of the pound.", Carol Mather, MP, parliamentary metrication debate, 27 October 1970.

Metrication logo

Metrication logo

The United Kingdom is in the process of phasing out the legal status of most non-metric units. Thus it uses a mix of metric and non-metric units for different purposes. The United Kingdom is currently in the process of abolishing the use of most non-metric units; as of 2000, all loose goods sold by reference to units of quantity had to be sold using metric units. UK policy is to eliminate by 2009-12-31 almost all non-metric units when used for goods and services sold by quantity. Goods and services sold by a description are not covered by weights and measures legislation. Thus, a fence panel sold as "6 foot by 6 foot" will continue to be legal after 2009 but a poll sold as "50 pence per linear foot" is illegal. Road signs will, however, remain non-metric. The only non-metric units allowed by the Community Directive for economic, public health, public safety or administrative use from 1 January 2000 are:

• the mile, yard, foot and inch for road traffic signs, distance and speed measurement,
• the pint for the dispense of draught beer and cider, and for the sale of milk in returnable containers,
• the acre for land registration, and
• the troy ounce for transaction in precious metals.
• fraction of inch caliber for amunition sizes.
• units of time.

File:MetricbritainLogo.gif

Draught beer and cider are the only goods that may not be sold in metric units in the United Kingdom; the only legal measures for these drinks when sold on draught are ⅓ pint (190 ml) (rarely encountered), ½ pint (284 ml) and integer multiples of the latter.

The use of metric units has been legal in the UK for all purposes since 1897. The idea was first discussed by a Royal Commission that reported in 1818 [1]. In 1862, the Select Committee on Weights and Measures favoured the introduction of decimalisation to accompany the introduction of metric weights and measures [2]. A further Royal Commission "on the on the question of the introduction of metric system of weights and measures" also reported in 1869 [3].

Despite the slow progress of metrication, its sole adoption was first recommended by the Committee on Weights and Measures (Hodgson Committee) in 1950, and accepted by the President of the Board of Trade in May 1965. As a result, metric units have been taught in UK schools since the late 1960s, and certain industries also converted or largely converted decades ago. For example the paper industry converted in 1970, and the construction industry between 1969 and 1972—although certain products continue to be produced to with reference to imperial trade names but made using metric dimensions in the factory, for example a 13 mm (trade name: half-inch) thick plasterboard.

Metric is the system of use in industry. Products that may appear to be imperial are actually manufactured to metric specifications, using metric drawings and made on metric machines. References to imperial units may persist in some areas, but this just an example of hidden metric.

External links

• British Weights and Measures Association (Anti-metric)
• UK metric association (pro-metric)
• UK Government Department of Trade and Industry (Policy statement)
• [http://www.cambridge-news.co.uk/news/letters/2005/09/08/5fdfad9b-3c39-40c6-a661-d4acb27f1df5.lpf Drop the Pint

References

1. English Linear Measures: an essay in origins, by Philip Grierson. 'The Stenton Lecture 1971', University of Reading.
2. The Basis of Measurement: Historical Aspects, by Thomas McGreevy. ISBN 0-948251-82-4
3. The Basis of Measurement: Metrication and Current Practice, by Thomas McGreevy. ISBN 0-948251-82-0