PSC 134.251(3)(a)(a) Each utility selling gas shall keep a chronological record of dates and results of tests and operations performed on the calorimeter to test and maintain accuracy. PSC 134.251(3)(b)1.1. Two days of each month shall be selected for the performance of an “as found” accuracy test, mechanical tests, adjustments, and an “as left” accuracy test of each recording calorimeter, and thereafter the specified accuracy tests, adjustments, and maintenance work shall be performed on the same days of each month insofar as practicable. PSC 134.251(3)(b)2.2. In making the accuracy tests on the calorimeter, the utility shall use reference natural gas which has been certified by the Institute of Gas Technology before cleaning parts or making any adjustments to either the tank unit or the recorder mechanism. The change from line gas to the certified gas should be made so as to have a continuous chart recording. The inlet pressure used should be the same for both calibration and subsequent operation. PSC 134.251(3)(b)3.3. If the “as found” accuracy test is within + or -3 B.t.u., no adjustment will be required and the instrument may be returned to service. If the “as found” accuracy test is not within + or - 3 B.t.u., maintenance shall be performed to restore the accuracy of the instrument. PSC 134.251(3)(b)4.4. In order that adequate information concerning each cylinder of natural gas which is to be used for the semi-monthly check tests be available at all times, the following information shall be entered on a form or in a log book provided for the purpose and also on a label or tag securely attached to each cylinder in which the gas is stored: PSC 134.251(3)(b)4.g.g. Heating value to be used in the semi-monthly accuracy tests. This heating value will not include any plus or minus values. For example, if the heating value is 1,000 + or - 0.9 B.t.u. per cubic foot, the heating value is 1,000 B.t.u. per cubic foot. PSC 134.251(5)(5) The original chart records produced by the recording calorimeters shall be dated, labeled, and kept on file for 6 years. A copy of the daily average heating value of gas and the results of the semi-monthly“as found” and “as left” test shall be sent to the commission each calendar month. PSC 134.251(6)(6) A gravitometer may be substituted for the calorimeter equipment required to control standby or peak shaving plants in subs. (1) and (5) provided the heat content of the standby or peak shaving gas produced does not directly affect the therm billing of the gas customer receiving it. PSC 134.251 HistoryHistory: Cr. Register, January, 1965, No. 109, eff. 2-1-65; cr. (6), Register, July, 1983, No. 331, eff. 8-1-83. PSC 134.26PSC 134.26 Meter testing and testing equipment. PSC 134.26(1)(1) Each public utility giving gas service is responsible for the accuracy of equipment used to measure service to its customers and all gas supplied by the utility shall be metered unless specific exemption is obtained from the public service commission. The utility shall own and maintain the equipment and facilities necessary for accurately testing the various types and sizes of meters used by the utility for the measurement of gas, shall make the tests required by these rules, shall maintain the measuring devices, and maintain their accuracy; unless arrangements are made to have the work done by others who have properly equipped laboratories, are approved by the commission and arrangements are also made to have equipment and procedures checked by the public service commission. A test by the manufacturer of a metering device is not acceptable unless witnessed by a utility representative. PSC 134.26(2)(2) Each public utility giving gas service shall own and maintain, except as provided in sub. (1), a meter prover of sufficient capacity to test meters in accordance with s. PSC 134.28. The meter prover shall be complete with all accessories needed for accurate meter testing, shall be suitably located for meter testing, and shall be protected from drafts and excessive temperature changes. The equipment shall be maintained in good condition and correct adjustment and be capable of determining the accuracy of service meters to within one-half of one per cent. When the meter prover is used to test temperature-compensating meters, there shall be present a temperature-indicating device to accurately determine the temperature of the prover to within + or - 1° Fahrenheit. PSC 134.26(3)(3) Each public utility giving gas service through turbine or rotary displacement type meters shall a) own and maintain, except as provided in sub. (1), a flow or volumetric meter of suitable capacity, together with necessary accessories, and it shall maintain such equipment in proper adjustment so that it will be capable of determining the accuracy of turbine or rotary displacement type meters to within one-half of one percent; or b) have a record of tests of each turbine or rotary displacement type meter made by an acceptable laboratory or by a manufacturer witnessed by a representative of the utility. The record should show that the test included a check of the recording device. PSC 134.26(4)(4) Each public utility giving gas service through orifice type meters shall own and maintain, except as provided in sub. (1), instruments for checking the diameter of the orifice, a water column for testing the pressure differential recorder, and a mercury column or a dead weight gauge tester for testing the static pressure recorder so that the utility will be capable of determining the accuracy of these orifices and recorders to within one-half of one per cent. PSC 134.26(5)(5) All instruments and equipment used for testing of meters shall be maintained in good condition and correct adjustment and be capable of determining the accuracy of service meters to within one-half of one percent. Bell type provers shall be checked at least once each 3 years against a standard by either the bottling or strapping method. All electrical and electronic equipment associated with testing equipment shall be tested every 6 months. PSC 134.26(6)(6) A rotary displacement type meter, when used as a standard for testing other service meters, shall be given a differential test every 6 months. An original differential test record of the standard meter shall be established and all future differential test results shall be recorded and compared with the original test record. When the test differential pressure differs from the original test record by more than 25% at approximately 25% of the capacity of the meter, the meter shall be cleaned and/or repaired. All associated electrical equipment shall be tested before each series of tests. Associated pressure and temperature correction equipment shall be tested every 6 months. PSC 134.26(7)(7) A diaphragm-type meter shall not be used as a standard for testing other service meters. PSC 134.26(8)(8) The temperature in the proving and meter storage rooms shall not vary by more than ±3° Fahrenheit, or testing shall be stopped. If the proving equipment can compensate for a temperature differential between the proving equipment and the meter, then testing may be performed within the proving equipment temperature specification. The proving and meter storage rooms shall be equipped with a temperature recording device. A meter shall be stored in the temperature controlled area a minimum of 12 hours before being tested. The meter shop shall be kept in a clean and orderly manner. PSC 134.26 HistoryHistory: Cr. Register, February, 1959. No. 38, eff. 3-1-59; am. (2), Register, January, 1965, No. 109, eff. 2-1-65.; am. (3) and (5), cr. (6) and (7), Register, April, 1969, No. 160, eff. 5-1-69; am. (2) and (5), cr. (8), Register, November, 1989, No. 407, eff. 12-1-89. PSC 134.27PSC 134.27 Meter accuracies. All meters shall be set as close to 100% accurate as possible. Diaphragm meters shall be considered correct for service if the results of the multiple tests called for agree within 1% and no test shows an error of more than 1% fast or slow. Turbine and rotary displacement type meters shall be considered correct for service when tested at approximately 10% of rated flow with accuracy between 2% slow and 2% fast, and at approximately 100% flow with accuracy between 1% slow and 1% fast and in the case of turbine type meters, have a spin test time equal to or greater than that on file with the commission under s. PSC 134.28 (6). In orifice type meters, the deviations in the diameter of the orifice shall not exceed the following: