8.1.2.22 Z AND ZB Test
The accuracy is given as:
AT = AR+AC+AV+AI
where
AT is the total accuracy (%)
AR is the basic relative accuracy (%)
AC is the calibration accuracy (%)
AV is the correction for voltage level (%)
AI is the correction for current level (%)
The value of AR is given in the table in section 1.1. of this chapter.
The values of the other factors are given below.
AC = 0.08% + (0.0000001% x FM)
AV = 0.08% + (0.000003% / VM)
AI = 0.08% + (0.0000003% / IM) + (0.03% x IB / IM)
where
FM is the measurement frequency (Hz)
VM is the measured voltage (V)
IM is the measured current (A)
IB is the bias current (A).