188.8.131.52 TR Test
The accuracy is based on the test conditions chosen to measure the turns ratio, and is given as:
AT = AR +AC+APV+ASV+AN
AT is the total accuracy (%)
AR is the basic relative accuracy (%)
AC is the calibration accuracy (%)
APV is the correction for primary voltage level (%)
APS is the correction for secondary voltage level (%)
AN is the correction for the turns ratio value (%)
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 = 0.1% + (0.00003% x FM)
APV = 0.1% + (0.01% / VPM)
ASV = 0.1% + (0.01% / VSM)
AN = 0.1% + (0.1 / NM)
FM is the measurement frequency (Hz)
VPM is the measured primary voltage (V)
VSM is the measured secondary voltage (V)
NM is the measured turns ratio (primary / secondary)
The accuracy for the test is given as:
AT = AP + AS
AT is the total accuracy (%).
AP is the accuracy of the primary winding measurement (%).
AS is the accuracy of the secondary winding measurement (%).
To determine the values of AP and AS use the accuracy specification for series inductance.