Where
A_T is the total accuracy (%)
A_R is the basic relative accuracy (%)
A_C is the calibration accuracy (%)
A_I is the correction for the current level (%)
A_OFF is the error in the compensation measurement (%)
A_ESI is the error in the current measurement from the source interface (%)
A_SRCE is the correction for the external source type (%)

The value of AR is given in the table in section 1.1 of this chapter
A_C       = 0.03% + (0.001 * F_M)
A_I        = 0.03% + (0.0001 / I_M) + (2 * I_M)
A_OFF   = (0.76% + (0.001 * F_M) ) * (0.3 / I_M)
A_ESI = 0.5%
A_SRCE = 0.5% for manual / line supply
           = 0.0% for analogue / amplifier and AT output transformer

F_M is the test frequency (Hz)
I_M is the measured current (A)

During a MAGX test, the AT3600 automatically applies the test voltage to the part under test and checks that the voltage has stabilised before recording measurements. The time that the voltage takes to stabilise will vary with the source type used and the nature of the part under test.

In general (and especially for source types 'Programmable' and 'AT Output Transformer'), the AT3600 will record a measurement very quickly, (typically in less than 0.5 seconds) which is desirable in a production test environment.

If the measurement were to be recorded after a longer period of time under power, slightly different readings may be obtained due to self-heating effects in the part under test. This effect may be noticed when comparing results taken using different source types or with slower measurement systems.

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