1.1 The purpose of this bulletin is to establish the test points that shall be applied to calibrate local radian standards used for certifying electricity calibration consoles pursuant to the Specifications for the Calibration, Certification, and Use of Electricity Measurement Apparatus (S-E-01).

2.0 Calibration of Local Radian Standards - W·, var·, VA· and Q·

2.1 Test Points. Local radian standards shall be calibrated at the test points prescribed in the table below.

*Voltage* (volts)	*Current* (amperes)
*Voltage* (volts)	0.25	0.5	1.25	2.5	5.0	10.0	25.0	33.3	50.0
120	A^*,B	A^*,B	A^*,B	A^*,B	A^*,B	B	A,B,C	A,B,C	A,B,C
240	A^*,B	A^*,B	A^*,B	A^*,B	A^*,B	B	A,B,C	A,B,C	A,B,C
277	B	B	B	B	B	B	A,B,C	A,B,C	A,B,C
345	B	B	B	B	B	B	A,B,C	A,B,C	A,B,C
360	B	B	B	B	B	B	A,B,C	A,B,C	A,B,C
480	B	B	B	B	B	B	A,B,C	A,B,C	A,B,C
600	B	B	B	B	B	B	A,B,C	A,B,C	A,B,C

Notes:

(1) Letters "A", "B", and "C" represent the current taps of the Radian.

(2) Tap A* as indicated in the above table shall be calibrated for watt hours only at a power factor (Pf) of 1.0 Pf.

2.2Calibration Errors. All calibration errors shall be established to a resolution of two digits to the right of the decimal.

2.3 Power Factors. W·, VA· (rms and avg) and Q· shall be calibrated at each of the test points prescribed in clause 2.1 at power factors of 1.0 Pf and 0.5 Pf. The var· function shall be calibrated at 0.0 Pf, 0.5 Pf, and 0.866 Pf.

2.4 Demand Function. The calibration of the equivalent demand functions is not required. The equivalent energy errors shall be used for demand functions.

2.5 Voltage and Current Function. The Radian shall also be calibrated for the voltage function and the current function at the respective voltages and currents indicated in the table of clause 2.1. The current function shall be calibrated at the "B" tap for all currents except 25 A, 33 A, and 50 A which shall be calibrated at all three taps.

2.6 Other Test Points. For the purposes of certifying consoles at test points for which the Radian is not calibrated, the error of the local radian standard at the closest calibrated test point shall be used. When the test point for calibrating the console lies equidistant between two calibrated Radian test points, the error of the lower test point shall be used.

3.0 Additional Information

For additional information regarding this bulletin, please contact the undersigned.

Guy Dacquay
Senior Program Officer
Electricity Measurement


		Created: 2003-07-08 Updated: 2005-01-25	Top of Page	Important Notices