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IM 704510-01E
Troubleshooting and Maintenance
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14.6 Performance Test
CAUTION
• Do not apply a voltage exceeding the maximum input voltage to the input
terminal of each instrument. This may cause damage to the input section.
• Do not apply external voltage to the output terminals of instruments. This may
cause damage to the internal circuitry.
Testing the Trigger Voltage Accuracy
Instruments Required
Prepare the following instruments.
DC voltage generator
• Voltage accuracy:
1 mV or better
• Recommended instrument: 7651 programmable DC voltage/current source
(by YOKOGAWA)
The procedure for testing the trigger voltage accuracy using the recommended
instruments is described below.
Connecting the Instruments
• Check that the power switch is turned OFF on all instruments before connecting the
instruments.
• Connect the output of the DC voltage generator to the input terminal (CH A/CH B) of
the TA720.
7651
PROGRAMAB LE DC SOURCE
TA720
OUTPUT
CH A
CH B
DC voltage generator (7651)
Instrument Settings
• TA720: Input settings: DC coupling, 1 M
Ω
, trigger level = 0 V
• 7651:
Output level:
4.000 V, 0 V, –4.000 V
Test Method
• Calibrate the TA720 after 30 minutes of warm-up.
• This test compares the applied DC voltage to the trigger level (slice level) set by the
TA720 and checks the error in the trigger level.
• The actual detection of the trigger level is done by monitoring the input indicator of the
TA720.
Test Procedure
1.
Connect the output of the 7651 to TA720 CH A.
2.
Set the output level of the 7651 to 4.000 V.
3.
Set the trigger level of the TA720 to 4.100 V.
4.
Set the TA720 in the measurement start condition.
5.
Decrease the trigger level of the TA720 in 5-mV steps. Gradually decrease the
trigger level and record the voltage at which the input indicator illuminates as VL.
6.
Set the trigger level of the TA720 to 3.900 V.