71M6521 Demo Board User’s Manual
Revision 2.18
© 2005-2009 TERIDIAN Semiconductor Corporation
Page: 55 of 111
4) Calculate the new calibration factors CAL_IA, CAL_VA, and PHADJ_A, using the formulae presented in
section 2.1.2 or using the spreadsheet presented in section 2.2.4.
5) Apply the new calibration factors CAL_IA, CAL_VA, and PHADJ_A to the meter. The memory locations
for these factors are given in section 1.9.1.
6) Test the meter at nominal current and, if desired, at lower and higher currents and various phase angles
to confirm the desired accuracy.
7) Store the new calibration factors CAL_IA, CAL_VA, and PHADJ_A in the EEPROM of the meter. If the
calibration is performed on a TERIDIAN Demo Board, the methods shown in sections 1.9.2 can be
used.
2.2.4 PROCEDURE FOR FAST CALIBRATION
The calibration procedure is as follows:
1)
Establish load voltage and current. The load angle must be exactly 0.00 degrees.
2) Wait 2 seconds.
3) Clear the accumulators (e.g. with CLI command
)1=2
)
4) Wait 30 seconds.
5) Disable the CE (e.g. with CLI command
CE0
)
6) Read accumulated values from MPU RAM registers and enter these in the spreadsheet supplied on the
Demo Kit CD-ROM. Use the addresses as listed in Table 1-13. Enter applied voltage and current as
well as the number of completed accumulation intervals in the spreadsheet.
7) Apply the measured IC temperature in register accessible at )14..
2.2.5 CALIBRATION SPREADSHEETS
Calibration spreadsheets are available from TERIDIAN Semiconductor. They are also included in the CD-ROM
shipped with any Demo Kit. Figure 2-3 shows the spreadsheet for three measurements with three phases in use (only
one phase needs to be used for the 71M6521 chip).
Figure 2-3 shows the spreadsheet for five measurements with three phases (only one phase needs to be used for the
71M6521 chip).
