ScopeMeter® Test Tool
Performance Verification
33
Probe Calibration Generator Test
To calibrate, connect a 10:1 or 100:1 probe as supplied with the Test Tool to input A (red
probe). Connect the probe tip and the probe ground lead with the probe cal terminals on the
lower left side of the Test Tool. See
(the figure is universal and shows a Test Tool
with four oscilloscope channels such as the model 190-204 or 190M-4).
1. Reset the Test Tool.
2. Press
A
to show the input A key labels.
3. Press
E
to select the 10:1 or 100:1 voltage probe for the calibration.
4. Press
E
to confirm and
1
to reopen the probe menu.
5. Press
3
(-PROBE A 10:1 ….).
6. Press
1
(- PROBE CAL…) and follow the instructions on the display.
7. Press
4
to start the probe calibration. The first step is to manually adjust the
square wave response to a pure square wave (pulse top must be straight). The trimmer is
located in the probe housing near the BNC and can be reached by rotating the center part
of the housing. For further information refer to the probe instruction sheet.
8. When done, press
4
to start the DC calibration automatically. The Probe
Calibration is OK if all instructions shown on the display are finished successfully.
Close the hole of the trimmer by rotating the center part of the housing. This is important
for safe use of the probe at high input voltages.
9. Repeat the procedure for channel B (blue probe). For the 4-channel test tools, repeat the
procedure for channel C (gray probe) and channel D (green probe).
Figure 12.
Probe Calibration Connection
This is the end of the Performance Verification Procedure.
Probe Cal
Probe Cal Reference
Note
VPS421 does not need adjustment.