Agilent Technologies 34970A, Service Manual

Page: 172 / 273

615 Ohms 10
µ
A source failed
This test configures the 10 V range with
the internal internal 10 M 100:1 divider A4U102 connected across the
input. The 10 µ A current source is connected. 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 the 1 A dc rage and
function. 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.
617 Ohms 100
µ
A source failed
This test configures the 10 V range
with the internal 10 M 100:1 divider A4U102 connected across the
input. The 100 µ A 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 5 V
±
1 V.
618
DC high voltage attenuator
This test configures to the 300 Vdc
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 –10 mV to 70 mV at the output of
the rms-to-dc converter.
619
Ohms 1 mA source failed
This test configures the 10 V range with
the internal 1 0 M 100:1 divider A4U102 connected across the input.
The 1 mA current source is connected. 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 to the 100 mV ac range
with the ac input grounded through A4K103. 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 the charge the
ac input capacitor A4C301. 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 ± 8.5 V into the ADC.
Chapter 6 Service
Self-Test Procedures
170