Bob Eager wrote:
On Wed, 8 Nov 2006 15:57:06 UTC, "Geronimo W. Christ Esq"
wrote:

Andy Wade wrote:

4. Multiply by the declared calorific value (CV - see last gas bill) to
get consumption in Megajoules.

I've always wondered why this is required. Does the calorific value vary ?

Yes. Not by much, but yes.

when I worked for BG, one of my jobs was to tabulate the output from
the terminals of CV into a graph.

Suppliers were "fined" for gas which fell below a certain CV.