69
When the correct password has been entered from the keyboard the display changes to the
opening screen of the calibration routine and calibration can proceed as described in the
Calibration Routine section. If an incorrect password is entered the message
INCORRECT
PASSWORD!
is shown for two seconds before the display reverts to the
UTILITY
menu.
With the opening screen of the calibration routine displayed after correctly entering the password,
the password can be changed by pressing
password
...
soft
−
key and following the procedure
described in Setting the Password. If the password is set to 0000 again, password protection is
removed.
The password is held in EEPROM and will not be lost when the memory battery back
−
up is lost.
In the event of the password being forgotten, contact the manufacturer for help in resetting the
instrument.
Calibration Routine
The calibration procedure proper is entered by pressing
continue
on the opening
Calibration screen; pressing
exit
returns the display to the
UTILITY
menu. Pressing
tests…
calls a menu of basic hardware checks used at production test; these are largely
self
−
explanatory but details can be found in the Service Manual if required. At each step the
display changes to prompt the user to adjust the rotary control or cursor keys, until the reading
on the specified instrument is at the value given. The cursor keys provide coarse adjustment, and
the rotary control fine adjustment. Pressing
next
increments the procedure to the next step;
pressing CE decrements back to the previous step. Alternatively, pressing
exit
returns the
display to the last CAL screen at which the user can choose to either
save new values,
recall old values
or
calibrate again.
The first two displays (CAL 00 and CAL 01) specify the connections and adjustment method. The
next display (CAL 02) allows the starting channel to be chosen; this allows quick access to any
particular channel. To calibrate the complete instrument choose the default setting of CH1. The
subsequent displays, CAL 03 to CAL 55, permit all adjustable parameters to be calibrated.
The full procedure is as follows:
CAL 03
CH1. DC offset zero.
Adjust for 0V ± 5mV.
CAL 04
CH1. DC offset at + full scale.
Adjust for + 10V ± 10mV.
CAL 05
CH1. DC offset at
−
full scale.
Check for –10V ± 3%
CAL 06
CH1. Multiplier zero.
Adjust for minimum Volts AC
CAL 07
CH1. Multiplier offset.
Adjust for 0V ± 5mV.
CAL 08
CH1. Waveform offset.
Adjust for 0V ± 5mV.
CAL 09
CH1. Output level at full
−
scale
Adjust for 10V ± 10mV.
CAL 10
CH1. 20dB attenuator
Adjust for 1V ± 1mV.
CAL 11
CH1. 40dB attenuator
Adjust for 0·1V ± ·1mV.
CAL 12
CH1. 10dB attenuator
Adjust for 2·236V AC ± 10mV.
CAL 13
CH1. Not used.
CAL 14
CH1. Not used.
CAL 15
CH1. Not used.
CAL 16
CH2. DC offset zero.
Adjust for 0V ± 5mV.
CAL 17
CH2. DC offset at + full
−
scale.
Adjust for +10V ± 10mV.
CAL 18
CH2. DC offset at
−
full
−
scale.
Check for –10V ± 3%
CAL 19
CH2. Multiplier zero.
Adjust for minimum Volts AC
CAL 20
CH2. Multiplier offset.
Adjust for 0V ± 5mV.
CAL 21
CH2. Waveform offset.
Adjust for 0V ± 5mV.
CAL 22
CH2. Output level at full
−
scale
Adjust for 10V ± 10mV.
CAL 23
CH2. 20dB attenuator
Adjust for 1V ± 1mV.