Voltage Surveys. Each utility shall make voltage measurements, using recording voltmeters, in order to determine if voltages are in compliance with the requirements contained in Regulation .02. Point of Measurement. Voltage measurements shall be made at the utility's service terminals. For single phase service, the measurement shall be made between the grounded conductor and the ungrounded conductors. For 3 phase service, the measurement shall be made between the phase wires. Voltage Records. All voltmeter records obtained under §A, above, shall be retained by the utility for at least 2 years and shall be available for inspection by the Commission's representatives. Notations on each chart shall indicate the following: Location where the voltage was taken; Time and date of the test; Results of the comparison of the recording voltmeter with an indicating voltmeter. Record of Corrective Action. If action is taken to correct the voltage conditions, the chart which records the voltage subsequent to the change shall be attached to the first chart so that the conditions before and after the change may be reviewed.