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3-21
IM 701210-05E
Making Preparations for Measurements
3
3.7
Compensating the Probe (Phase Correction)
When making measurements using a probe on the following modules, be sure to perform
phase correction of the probe first.
• High-Speed 10 MS/s, 12-Bit Isolation Module: 701250 (HS10M12)
• High-Speed High-Resolution 1 MS/s, 16-Bit Isolation Module: 701251 (HS1M16)
• High-Speed 10 MS/s, 12-Bit Non-Isolation Module: 701255 (NONISO_10M12)
• High-Voltage 100 kS/s, 16-Bit Isolation Module (with RMS): 701260 (HV (with RMS))
• Acceleration/Voltage Module (with AAF): 701275 (ACCL/VOLT)
• Frequency Module: 701280 (FREQ)
CAUTION
Never apply an external voltage to the probe compensation output terminal, as
damage to the instrument may result.
Procedure
1.
Turn ON the power switch.
2.
Connect the probe to the input terminal to which the signal is to be applied.
3.
Connect the probe’s tip to the probe compensation output terminal on the front
panel and connect the earth wire to the functional earth terminal.
4.
Perform auto setup according to the procedure described in section 4.5,
“Performing Auto Setup.”
5.
Insert a flat-head screwdriver to the phase adjustment knob and turn the
variable capacitor to make the displayed waveform a correct rectangular wave.
Probe compensation
output terminal
Functional
ground terminal
Phase adjustment
knob
Explanation
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, waveforms cannot be displayed
correctly. In addition, the input capacitance varies depending on the probe. Thus, the
variable capacitor (trimmer) provided on the probe must be adjusted. This adjustment is
called phase correction.
When using the probe for the first time, make sure to perform phase correction.
Furthermore, the appropriate input capacitance varies according to which channel is
used, so probe compensation is required when the probe is switched from one channel
to another.