3-11
IM 704510-01E
Before Starting Measurements
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Procedure
1.
Turn ON the power to the TA720 and the DL1700 Series Digital Oscilloscope.
2.
Set the waveform acquisition conditions of the DL1700 Series Digital Oscilloscope
so that approximately two periods of the waveform can be viewed in its entirety.
For the procedure, see the user’s manual for the DL1700 Series Digital
Oscilloscope.
3.
Insert a flat-blade screwdriver to the phase correction hole of the probe and turn
the variable capacitor to make the displayed waveform on the waveform monitor a
correct rectangular wave (see explanation).
Explanation
The Necessity of Phase Correction of the Probe
If the input capacity of the probe is not within the adequate range, the gain across
different frequencies will not be uniform. Consequently, a correct waveform cannot be
input to the measurement circuit of the TA720. However, the input capacity of each
probe is not necessarily all the same. Therefore, the probe has a variable capacitor
(trimmer) that allows the input capacity to be adjusted. This adjustment is called phase
correction.
When using the probe for the first time, make sure to perform phase correction. The
appropriate input capacity varies depending on the channel of the TA720. Therefore,
phase correction must also be performed when the connected channel is changed.
Compensation Signal
Waveform type: Rectangular wave
Frequency:
1 kHz
Voltage:
1 Vp-p
Differences in the Waveform Caused by the Phase Correction of the Probe
Correct waveform
Over compensated
(the gain in the high
frequency region is up)
Under compensated
(the gain in the high
frequency region is low)
3.6 Calibrating the Probe (Phase Correction)
