Wis. Admin. Code § PSC 113.0706
(1) Each utility shall submit to a public service commission-approved calibration facility once each year a portable digital standard watthour meter and once each 2 years a portable digital indicating voltmeter or multimeter, unless waived by the commission under the provisions of s. PSC 113.0902 (1). Smaller Class C and D utilities, may be allowed to continue to use the older electromechanical portable watthour standard for a reasonable future time period, if so authorized by the commission.
Note: The rapid movement to the newer fully-electronic digital watthour standards by the measurement industry has limited a laboratory’s ability to get replacement parts needed to maintain and calibrate the older electromechanical standards. All utilities have been advised of the need to acquire electronic/digital standards when it is reasonably feasible to replace the older obsolete electromechanical standards.
(2) Each utility shall be equipped with or otherwise arrange to have available when needed, portable digital indicating and recording voltmeters having internal memory channels of an accuracy and quantity sufficient to make a determination that the service voltage supplied to their customers complies with the requirements set forth in ch. PSC 113. This instrument shall be maintained with an error no greater than 0.8% of full scale.
Note: (1) Caution should be exercised in using digital meters in areas of high electrical fields such as in close proximity to substations, high voltage lines, transformers, regulators, etc., as unstable or erroneous readings may result.
(2) Those utilities which operate standards laboratories will require primary or laboratory grade instruments of a higher accuracy class than required above.
History: Cr. Register, July, 2000, No. 535, eff. 8-1-00.