http://www.legislation.gov.uk/uksi/1990/1635/regulation/6/made

The Gas (Testing of Apparatus and Equipment) Regulations 1990

Gas supply

King's Printer of Acts of Parliament

2016-03-21

GAS

These Regulations apply to public gas suppliers, in so far as the number of therms supplied by them is calculated on the basis of actual calorific values of the gas (“relevant suppliers”), who have been directed by the Secretary of State pursuant to the Gas (Alternative Method of Charge) Regulations 1990 to provide and maintain premises, apparatus or equipment for the purpose of making determinations of actual calorific values of gas supplied by them.