I-Limit(Model487); Integration - Keithley 486 Instruction Manual

SECTION 3
Front Panel Operation
Press MENU. The stored reading at memory loca-
tion 001 will be displayed. For example, if the stored
reading is -l.OOOOOmA, the following will be dis-
played:
-1.00000 rd.
LOC 001
The stored readings at the other memory locations
(and MIN and MAX) can be examined by using the
ADJUST controls. The4 and b keys position the cur-
sor on the digit to be adjusted and the rotary knob in-
crements or decrements the memory location nun-
her from the selected digit. Decrementlng the value
from 001 displays the maximum and minimum
readings.
To exit from data recall press MENU to display the
next menu item, or press SHIFI and then EXIT to exit
from the menu.
NOTES:
1. The message "NO DATA" on the small display, indi-
cates that there are no readings stored in the buffer.
2. Turning off power, performing factory initialization,
defaultsrecallorsendinga DCLorSDC overthebw,
clears the buffer (NO DATA).
3.8.3
I-Limit (Model 487)
This menu item is used to check or change the current
limit setting of the V-Source of the Model 487. Details on
I-limit is contained in paragraph 3.6.4.
I-Limit Selections:
2.5mA I-limit setting of 2.51~4
25~
I-limit setting of 25+4
Perform the following steps to check or change the I-
hit:
Press and release MENU until the currently selected
I-limit is displayed. For example, if I-limit is 25pA,
the following message will be displayed:
ILmm-
2-w.
To retain this I-limit setting, proceed to step 3 or 4.
Use the rotary knob or the 4 and b keys to display
the alternate I-limit.
3. Enter the displayed I-limit by pressing MENU. The
next menu item will be displayed.
4. To exit from the menu, press SHIFT and then EXIT.
The instrument will return to the normal measure-
ment display state.
3.8.4 Integration
This menu selection is used to check or change the inte-
gration period for A/D conversions.
Integration Period Selections:
FAST
LINE6OHZ
LINE5OI-u
1.6msec integration (4-l /2 digit
resolution)
Line cycle 06.67msec) integra-
tion (5-l/2 digit resolution)
Line cycle (20msec) integration
(5-l /Z,digit resolution)
The selectable integration periods offer a trade-off be-
tween speed, resolution and noise rejection. The fast inte-
gration period provides the fastest measuements and
should be used when speed is the most important consid-
eration. The line cycle integration periods provide slower
but more stable (quieter) measurements by rejecting
power line noise. To achieve the most stable measure-
ments, select the line cycle period that matches the avail-
able line frequency.
Perform the following steps to check or change the in&
gration period:
1.
2.
3.
4.
Press and release MENU until the currently selected
integration period is displayed. For example, if the
integrationperiodiscurrentlysetfor60Hzlinecycle,
the following message will be displayed:
JNTEGRATE
LINEXOHZ
To retain this integration period, proceed to step 3 or
4.
Use the rotary knob or the 4 and fi keys to display
the desired integration period.
Enter the displayed integration period by pressing
MENU. The next menu item will be displayed.
To exit the menu, press SHIFI and then EXIT. The in-
strumentwill return to the normal measurement dis-
play state.
NOTE: Menu selection DEFAULT SAVE (see paragraph
3.8.6) can be used to save the selected integration period
as the power-up default condition.
3-18