Tektronix IsoVu TIVP Series, Руководство пользователя

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Table 11: Measurement problems and possible solutions
Problem Remedy
DC offset is present in signal
• Run SELF CAL
• Ensure the input signal is within the selected tip’s dynamic range
The Square Wave edge appears
“smoothed”, rolled off, or
uncompensated
• Run SELF CAL
• Make sure the scope bandwidth filter is set to full bandwidth
• Make sure the input signal is not overdriving the probe input
The measured amplitude is smaller
than expected
• The input signal may be “railed”
• Make sure the input signal is within the dynamic range of the selected probe tip
• Apply offset to bring the input signal within the dynamic range of the selected
probe tip
DC measurement inaccuracy
• Run SELF CAL
• Set the record length to at least 200 µs (longer is better) to allow time for the
optical components to settle on the correct DC value
There is too much noise and you
cannot accurately measure small
signals
• Select a sensor tip cable with lower attenuation
• Set the oscilloscope vertical scale to a smaller value
• Manually select a lower range to lower noise
There is no signal detected; the
waveform is a flat line
• Remove the sensor tip cable and check its continuity, referencing the input
impedance table
• Try putting a signal directly into the probe head SMA to check if just the probe
tip or the probe itself is broken
The probe head loses power
intermittently
• Make sure the probe head is within its operating temperature range
• Add external cooling; such as a small desktop fan
There is too much common mode
noise
• Try to remove any accessories, flying leads, or exposed wires between the test
point and the probe tip
• Use an MMCX tip with an MMCX test point either designed into the board or as
an unplanned test point
Repack the measurement system for shipment
If you need to return the measurement system to Tektronix for repair, use the original packaging. If this is unavailable or not
fit for use, contact your Tektronix representative to obtain new packaging.
When you return the measurement system to Tektronix, attach a tag showing the following information:
• Name of the product owner
• Address of the owner
• Instrument serial number
• A description of problems encountered and/or service required
User service
TIVP Series IsoVuTM Measurement System User Manual 49