2 Terms and Symbols
2.1 Terms
2.1.1 Electrical measuring
The measurement of real-time electrical parameters by electrical means.
2.1.2 Energy metering
The metering of energy parameters.
2.1.3 General electrical measuring meter
A meter used to measure，selectively measure and record the electrical operating parameters of electrical installations circuits from time to time.
2.1.4 Pointer-type meter
A meter indicating measured values with the aid of the pointer and scale.
2.1.5 Digital-type meter
A meter digitally displaying measured values directly on display.
2.1.6 Energy meter
An instrument measuring active（reactive）power energy data.
2.1.7 Impulse energy meter
A combination of energy metering components and pulse devices.
2.1.8 Multifunctional energy meter
An energy meter comprising measuring units and data process units，not only capable of metering unidirectional or bidirectional active（reactive）power energy，but also capable of measuring the energy demand at different times and directions，and displaying，storing and outputting data.
2.1.9 Voltage loss time counter
An instrument exclusively used for calculating and displaying the voltage loss time of voltage circuit of energy meters.
2.1.10 Energy tariff point
A metering point where power producers and grid operators settle the energy trading.
2.1.11 Electrical measuring transducers
A device intended for converting the measured quantities to DC current，DC voltage or digital signals.
2.1.12 Calibration value for transducers
The value of a certain quantity which is obtained from changing the nominal value of transducers through adjusting it according to the specific needs of users.
2.1.13 Measuring instrument accuracy class
The class of measuring instruments and/or accessories which meet certain measuring requirements and are intended to ensure that the permissible errors and variations are within the specified limits.
2.1.14 Measuring instrument intrinsic error
Errors of measuring instruments and/or accessories under reference conditions.
2.1.15 Total measuring error
A composite error resulting from the measuring instruments，transformers and the secondary measuring circuits thereof.
2.1.16 Energy tariff equipment
The devices used for measuring energy parameters at energy tariff point，including a variety of energy meters，voltage and current measuring transformers and their secondary circuits，energy metering cabinets（boxes）.
2.1.17 Energy tariff meter
An energy meter configured in energy tariff device.