Fluke 123/124/125
Service Manual
3-16
3.5.9 Input A and B DC Voltage Accuracy Test
WARNING
Dangerous voltages will be present on the calibration source and
connecting cables during the following steps. Ensure that the
calibrator is in standby mode before making any connection
between the calibrator and the test tool.
Proceed as follows:
1. Connect the test tool to the 5500A as for the previous test (see Figure 3-5).
2. Select the following test tool setup:
• Press
select auto ranging (AUTO in top of display).
• Press
to open the INPUT A MEASUREMENTS menu, and choose:
MEASURE on A: Vdc
• Press to open the INPUT B MEASUREMENTS menu, and choose:
INPUT B: ON | MEASURE on B: Vdc
• Using change the time base to select manual time base ranging, and lock the
time base on 10 ms/div.
• Fluke 123/124: press
/ to open the SCOPE INPUTS menu.
• Fluke 123/124: press
to open the SCOPE OPTIONS menu, and choose :
SCOPE MODE: NORMAL | WAVEFORM MODE: SMOOTH
• Fluke 125: press to open MENU.
• Fluke 125: press
to open the TRIGGER menu, and choose :
UPDATE: FREE RUN
• Fluke 125: press
to open the SMOOTH menu, and choose :
WAVEFORM: SMOOTH
• Move the Input A and Input B ground level (indicated by zero icon ) to the center
grid line. Proceed as follows:
⇒ Press
to enable the arrow keys for moving the Input A ground level.
⇒ Press
to enable the arrow keys for moving the Input B ground level.
⇒ Using the
keys move the ground level.
3. Using
set the Input A and B sensitivity to the first test point in Table 3-2.
The corresponding range is shown in the second column of the table.
4. Set the 5500A to source the appropriate DC voltage. Set the 5500A to Operate (OPR).
5. Observe the main reading and check to see if it is within the range shown under the
appropriate column.