HP 181A manual CAL Unsecure

Chapter 2 Service

About the HP 53131A/132A Calibration Menu

	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.

2

Assembly-Level Service Guide 2-7