Utility Settings 22
Keysight InfiniiVision 3000T X-Series Oscilloscopes User's Guide 353
 
• Every two years or after 4000 hours of operation.
• If the ambient temperature is >10° C from the calibration temperature.
• If you want to maximize the measurement accuracy.
The amount of use, environmental conditions, and experience with other 
instruments help determine if you need shorter User Calibration intervals.
User Calibration performs an internal self-alignment routine to optimize the signal 
path in the oscilloscope. The routine uses internally generated signals to optimize 
circuits that affect channel sensitivity, offset, and trigger parameters.
Performing User Calibration will invalidate your Certificate of Calibration. If NIST 
(National Institute of Standards and Technology) traceability is required, perform 
the "Performance Verification" procedure in the Service Guide using traceable 
sources.
To perform user calibration:
1 Disconnect all inputs from the front and rear panels, including the digital 
channels cable on an MSO, and allow the oscilloscope to warm up before 
performing this procedure.
2 Press the rear-panel CAL button to disable calibration protection.
3 Connect short (12 inch maximum) equal length cables to each analog channel's 
BNC connector on the front of the oscilloscope. You will need two equal-length 
cables for a 2-channel oscilloscope or four equal-length cables for a 4-channel 
oscilloscope.
Use 50W RG58AU or equivalent BNC cables when performing User Calibration.
For a 2-channel oscilloscope, connect a BNC tee to the equal length cables. 
Then connect a BNC(f)-to-BNC(f) (also called a barrel connector) to the tee as 
shown below.