Calibrating The Probe - Iwatsu DS-8814 Operation Manual

Calibrating the probe

To measure correct waveforms, it is necessary that the phase of the probe has been
adjusted properly. Before using the probe, follow the steps below to adjust the phase.
Insert the screwdriver supplied with the instrument into the probe phase adjustment
hole and turn the variable capacity to change the displayed waveform to the correct
square waveform. Calibrate the probe according to the operation manual supplied
with the instrument.
Correctly compensated
waveform
Adjust it so that this
part may be flat.
Cautions for use of shielded cable
If the shielded cable is directly connected to a circuit to be measured, the
following effects may arise.
1. Noise affects the instrument adversely.
2. Frequency band width is reduced.
3. Load effects may become large.
If 10:1 probe is used, the input RC is changed from "1 MΩ, 20 pF" to "10 MΩ,
13 pF". This may reduce the load to a circuit to be measured, ensuring highly
accurate measurement.
[Example]
the capacity becomes 150 pF.
Excessive
compensation
Insufficient
compensation
If the shielded cable with a capacity of 100 pF/m is 1.5 m long,
13