Section 501.230  Coriolis Meters

a)         A utility shall install a Coriolis meter in accordance with the recommendations of AGA Report #11, Measurement of Natural Gas by Coriolis Meter, XQ1301 (February 2013).

b)         A utility shall verify the proper operation of an installed Coriolis meter at least every 12 months by verifying that the meter meets the manufacturer's tolerances using, at a minimum, all of the following inspection requirements:

1)         Meter zero flow check;

2)         Meter sensor check; and

3)         Meter transmitter check.

c)         A utility shall calibrate a Coriolis meter at least every 120 months. However, if the utility can demonstrate that the meter meets the manufacturing tolerances set forth in Section 501.220(b) and the utility conducts an annual inspection of the meter body to ensure that the meter body has not incurred damage that would affect the meter's accuracy, the utility may forego the 120-month calibration requirement.

d)         When a utility removes a Coriolis meter from service, the utility shall verify the meter's existing accuracy prior to altering the operation of the meter. This verification replaces the requirements of Section 501.170(d) for Coriolis meters.

e)         A utility shall maintain the most recent five years of inspection records. A utility shall also maintain documents for each Coriolis meter's most recent accuracy test, the prior accuracy test, and the dates of any other accuracy test that occurred during the prior 10 years.

(Source:  Amended at 41 Ill. Reg. 351, effective December 29, 2016)