Technical data
615 Ohms 10 uA source failed This test configures to the 10 V dc range
with the internal 10 M 100:1 divider
U102A connected across the input.
The 10
µA ohms current source is connected. The compliance limit of the
current source is measured. A 20 ms
ADC measurement is performed
and the result is checked against a limit of 7.5 V
± 3 V.
616 DC current sense failed This test configures to the 3 A dc range.
A 20 ms
ADC measurement is performed and the result is checked
against a limit of 0 A
± 5 A. This test confirms that the dc current sense
path is functional. The test limit is set wide because
K101 does not open
the current input during self-test. This test should catch a dc current
sense failure without causing false failures when current inputs are
applied during self-test.
617 Ohms 100 uA source failed This test configures to the 10 V dc range
with the internal 10 M 100:1 divider
U102A connected across the input.
The 100
µA ohms current source is connected. The compliance limit of
the current source is measured. A 20 ms
ADC measurement is
performed and the result is checked against a limit of 7.5 V
± 3 V.
618 DC high voltage attenuator failed This test configures to the 1000
V dc range. The 500 nA ohms current source is connected to produce a
nominal 5 V signal. A 20 ms
ADC measurement is performed and the
result is checked against a limit of 5 V
± 1 V.
619 Ohms 1 mA source failed This test configures to the 10 V dc range
with the internal 10 M 100:1 divider
U102A connected across the input.
The 1 mA ohms current source is connected. The compliance limit of the
current source is measured. A 20 ms
ADC measurement is performed
and the result is checked against a limit of 7 V
± 3.5 V.
620 AC rms zero failed This test configures for the 100 mV ac range with
the ac input grounded through
K103. The internal residual noise of the
ac section is measured and checked against a limit of –10 mV to 70 mV
at the output of the rms-to-dc converter.
621 AC rms full scale failed This test configures for the 100 mV ac range.
The 1 mA ohms current source is switched on to charge the ac input
capacitor
C301. This produces a pulse on the output of the rms-to-dc
converter which is sampled 100 ms after the current is applied. A 20 ms
A/D measurement is performed and checked against a limit of 10 V
± 8 V
into the
ADC.
6
Chapter 6 Service
Self-Test Procedures
123