Wisconsin Administrative Code › Public Service Commission › Chapter PSC 134 - Standards For Gas Service › Section PSC 134.251 - Use of recording calorimeter for therm billing

Current through June 24, 2024
(1) In the
			 application of gas rates based on the therm, a recording calorimeter shall be
			 used to determine the heating value of the gas being distributed to utility
			 customers. These calorimeters will be located as set forth in s.
			 PSC 134.25(2)
			 and (3). They shall have such accuracy
			 characteristics as to be able to measure the heating value of the gas to within
			 + or -2 B.t.u., shall be able to reproduce these readings to within +or - 2
			 B.t.u., and shall be able to hold their accuracy over an extended period of
			 time. The instruments shall be installed in accordance with the manufacturer's
			 recommendations.
(2) Each utility
			 selling gas shall file with the commission a complete installation report
			 stating the following information: location of calorimeter, kind of gas tested,
			 type of scale, uniform or split scale range, date installed, publication number
			 of manufacturer's applicable book of instructions, outline of the building, the
			 location of the calorimeter or calorimeters within the building, the size,
			 length, gas pressure, and general route of the gas sample pipe from the supply
			 main to each calorimeter and location of all secondary equipment necessary for
			 the operation of the recording calorimeter.
(3)
(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.
(b) Twice every month the
			 following tests shall be made:
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.
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.
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.
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:
a. Institute of Gas
			 Technology Cylinder Number.
b.
			 Institute of Gas Technology Certificate Number.
c. Date cylinder was certified.
d. Date cylinder was received by the
			 utility.
e. Heating value certified
			 by Institute of Gas Technology.
f.
			 Basis of the heating value in subd. 4. e.
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.
h. Basis of the heating value in subd. 4.
			 g.