Paragraph 3 Maximum permissible error

(1)

Where a cold-water meter is used for trade within a flowrate range set out in column 1 of the following Table, it must operate within the maximum permissible error specified for that flowrate range set out in column 2 of that Table.

Column 1	Column 2
Flowrate range	Maximum permissible error as a percentage of quantity delivered
Q₁to ˂ Q₂	± 6%
Q₂ to and including Q₄	± 2.5%

(2)

For the purposes of that Table—

(a)

“Q₁” is the lowest flowrate at which the cold-water meter provides indications that satisfy the requirements concerning the maximum permissible errors;

(b)

“Q₂” is the flowrate value occurring between the permanent and minimum flowrates, at which the flowrate range is divided into two zones, the upper zone and the lower zone, each zone having a characteristic maximum permissible error;

(c)

“Q₃” is the permanent flowrate; and

(d)

“Q₄” is the highest flowrate at which the cold-water meter operates in a satisfactory manner.