HP 53131A, Assembly And Service Manual

Page: 103 / 254

Chapter 2 Service
About the HP 53131A/132A Calibration Menu
Assembly-Level Service Guide 2-7
2
The Calibration menu, illustrated on page 2-8, allows you to:
• view the calibration security status of the Counter (CAL SECURE or
CAL UNSECURE)
• initiate the Counter’s calibration routines, which can perform
automatic calibration of the voltage offset and gain of the front-end
input amplifiers (CAL: OFFS 1 / 2 ?, GAIN 1 / 2?), of the optional
timebase (CAL: TIMEBAS?), and of the differences in electrical
path-length between channels 1 and 2 (CAL: TI QUIK? and
CAL: TI FINE?)
• secure against calibration by entering the security code while the
Counter is unsecured (CODE: )
• unsecure for calibration by entering the security code while the
Counter is secured (CODE: )
• change the security code by entering a new code while the Counter is
unsecured (CODE: )
• view the calibration count, which indicates the number of times that
the Counter has been calibrated (CAL COUNT?). The calibration
count increments up to a maximum of 32,767 after which it wraps
around to 1. A calibration count of 0 indicates that the Counter is
completely uncalibrated. (The calibration count is unaffected by
interpolator calibration.)
• get Help (HELP: ) with any of the following:
– how to calibrate (CAL?),
– how to secure (SECURE?), and
– how to change the code (CODE?)
NOTE A good precaution is to use an HP-IB program (see the programming
example titled “To Read and Store Calibration Data” in Chapter 3 of the
Programming Guide) to read and store the calibration factors prior to
initiating any calibration.