5.3 Periodic Inspection. Periodic inspection of meters Is required to
determine whether they are measuring accurately. The time interval between
inspections should be based on local conditions and the amount of use. The
manufacturer's representative in any particular area should be familiar with
local conditions and capable of assisting in the preparation of a schedule for
periodic inspection of meters.
6. ACCURACY . Accuracy limits for water meters have been established by
industry. For the meters discussed in this section, limits are based on tests
run at four different rates of flow; maximum, intermediate, changeover, and
minimum. The accuracy limits for the maximum and intermediate rates are from
97 to 103 percent of the quantity measured. The limits for the changeover
rate are from 90 to 103 percent. For the minimum test flow rates shown in
Table 4-3, compound meters shall register not less than 95 percent of the
actual quantity measured.