Agilent Technologies 54853A, Service Manual, Page: 101 / 194

Chapter 4: Calibration
To run the self calibration
4–7
To run the self calibration
The self calibration uses signals generated in the oscilloscope to calibrate channel sensitivity,
offsets, and trigger parameters. You should run the self calibration
• yearly, or according to your periodic needs,
• when you adjust or replace the acquisition assembly or acquisition hybrids,
• when you replace the hard drive or any other assembly,
• when the delta temperature is more than
±
5
°
C different than the last calibration, or
• after performing incoming performance verification and before performing outgoing
performance verification.
Equipment Required
Self calibration
1
Let the Oscilloscope Warm Up Before Running the Self Calibration.
The self calibration should only be done after the oscilloscope has run for 30 minutes at ambient
temperature with the cover installed. Calibration of an oscilloscope that has not warmed up may
result in an inaccurate calibration.
2
Pull down the Utilities menu and Select Calibration.
3
Click the check box to clear the Cal Memory Protect condition.
You cannot run self calibration if this box is checked. See figure 4-3.
Equipment Critical Specifications Recommended Model/Part
Adapter (supplied with 54854A & 54855A - 2
required for 54855A calibration) 3.5 mm (f) to precision BNC No substitute Agilent 54855-67604
Shorting Cap (supplied with all 3 models) BNC (m) Agilent 1250-0929
Cable Assembly 50
Ω
characteristic impedanceBNC (m)
connectors <= 12 inch length
Agilent 10502A or Agilent 8120-1838
Cable Assembly (cal cable supplied with 54855A) No substitute Agilent 54855-61620
10 MHz Signal Source (required for time scale
calibration) Frequency accuracy better than 0.4ppm Agilent 53131A with Opt. 010* or Agilent 5071A
or Symmetricom 58503B **
* Requires time base calibration once every 6 months. Should not be powered off for more than 24 hours after time base calibration.
** Requires link to GPS
Calibration time
It will take approximately 20 minutes to run the self calibration on the oscilloscope, including the time
required to change cables from channel to channel.