Section 460.2351. Meters and associated metering devices; inspections and tests.

Inspections and tests of meters and associated metering devices shall be made by, or on behalf of, each utility as follows:

(a)   A meter or an associated metering device that is not included as a part of the meter, or both, shall be inspected and tested before  being placed in service, and the error shall be not more than 1.0%. In place of this requirement, methods of sample testing that  are   acceptable   to   the commission may be used.

(b)   A meter or an associated metering device, or both, shall be tested after it is removed from service. Such tests shall be made before the meter or associated metering device is adjusted, repaired, or retired.

(c)   A repaired meter or a meter that is removed from service shall be leak-tested before being returned to service,  subject   to   the   following requirements:

(i)    If tested in the field, a meter shall be tested at the actual meter operating pressure of the system.

(ii)   If tested in the shop, a meter shall be subjected  to  an  internal

pressure test of not less than 3.0 pounds per square inch gauge pressure and, in addition, any meter that will operate above 3.0 pounds per square inch gauge pressure shall be so marked on the meter and shall be subjected to 1 of the following tests:

(A)   An internal pressure test of not less than the manufacturer's rated operating pressure.

(B)   An internal pressure test at 10% above the maximum operating pressure to which the meter could be subjected.

(C)  Any suitable test that is acceptable to the commission.

(iii)    During the pressure test, the meter shall be checked for leaks by 1 of the following tests:

(A)  Immersion test.

(B)  ) Soap test.

(C)  Pressure drop test of a type that is acceptable to  the commission.

(d)   As part of its rate book, a utility shall file, for commission approval, a statement of its policy with regard to testing  meter   accuracy upon a customer's request. In the absence of a filed  policy  approved  by the commission,  the   utility  shall adhere to  both   of  the    following provisions:

(i)   A utility shall test meter accuracy upon the request of a customer if the customer does not request a test more than once every 2 years and if the customer agrees to accept the results of the test as the basis for determining the difference claimed. A charge shall not be made to the customer for the first test in any 5-year period, but if subsequent tests during the same period, for the same customer, show the meter to be within the allowable limits of accuracy, the utility may charge the  customer  an amount for subsequent tests which is uniform and which does not exceed the utility's direct cost thereof, plus a reasonable charge for administrative overhead. The customer may be present at the test if he or  she  makes   a request before the test.

(ii)   A written report shall be made to the customer by the utility. The report shall state the results of the test. A record of the test  shall   be kept by the utility.

(e)    A utility shall make periodic tests of meters, associated  devices,  and instruments to ensure their accuracy. The tests shall be conducted according to the following schedule, unless otherwise   authorized    by  the commission:

(i)   Positive displacement diaphragm-type meters that have capacities of 500 cubic feet per hour and under 10 years.

(ii)   Positive displacement diaphragm-type meters that have capacities over 500 cubic feet per hour 7 years.

(iii)    Other meter types, such as proportional, rotary, and turbine, may be tested in place when possible 2 years.

(iv)   Orifice meters 6 months.

(v)    Gas instruments, such as base volume, base pressure, and base temperature-correcting devices, shall be removed and checked  for calibration at intervals that correspond to the schedule for their associated meters and shall be checked  for  calibration   in   place  at intervals of not more than 2 years.

(vi)   Test bottles, 1 cubic foot 10 years.

(vii)   Deadweight testers 10 years.

(viii)   Certified test meters 10 years.

(ix)     Meter testing systems shall be calibrated when first installed and after alterations, damages, or repairs that  might  affect accuracy.   To assure that the accuracy of a meter testing system is  maintained  on   a

continuous basis, a daily leakage test shall be made and  a   weekly  accuracy test with a comparison meter of known accuracy shall be made. If the test results differ by more than plus or minus 0.5% from the comparison meter, the cause of the error shall be determined and necessary corrections shall be made before the system is reused. The comparison meter shall be checked at an interval of 1 month.

History: 1979 AC; 1993 AACS.