HP 83487A User Manual page 41

C A U T I O N
C A U T I O N
drawing that shows each switch's function and protected position. Refer to the
optional HP 83480A, 54750A Service Guide for more details about the main-
frame calibration, and the position of the rear-panel memory protect switches.
To prevent access to the mainframe calibration switch, place a sticker over the
access hole to this switch.
Do not attempt a Mainframe calibration without consulting the HP 83480A,
54750A Service Guide.
A mainframe calibration should be performed on a periodic basis, annually, or
when the ambient operating temperature has changed by and remains 5°C dif-
ferent than the operating temperature at which the last mainframe calibration
was performed. To see how much the operating temperature has changed
since the last mainframe calibration and the date of the last mainframe calibra-
tion, check the Calibration status by pressing the following key sequence:
Utility, Calibrate, and then Cal status on.
The temperature change is displayed at the top of the display as shown in the
following figure.
Figure 3-1. Current Frame ∆ ∆ ∆ ∆ Temp condition
Calibration Overview
Factory Calibrations
3-5