Keithley 6485 Instruction Manual page 8

SCPI programming ................................................................... 1-18
Optional command words ................................................. 1-19
Query commands ............................................................... 1-19
2 Measurement Concepts
Measurement overview ............................................................... 2-2
Performance considerations ........................................................ 2-2
Warm-up period ................................................................... 2-2
Autozero .............................................................................. 2-2
SCPI programming ..................................................... 2-3
SYSTem:AZERo[:STATe] <b> .......................................... 2-3
Connection fundamentals ........................................................... 2-3
Input connector ........................................................................... 2-3
Maximum input levels ......................................................... 2-4
Low noise input cables ........................................................ 2-5
Basic connections to DUT ................................................... 2-6
Connections .................................................................. 2-6
Voltages greater than 220V ................................................. 2-6
Input voltage overload (OVRVOLT message) ..................... 2-9
Test fixture ........................................................................... 2-9
Test fixture chassis ..................................................... 2-10
Guard plate ................................................................. 2-10
Connectors, terminals, and internal wiring ................ 2-10
Handling and cleaning test fixtures ............................ 2-10
Input protection ................................................................. 2-11
Floating measurements ...................................................... 2-12
Zero check and zero correct ..................................................... 2-13
Zero check ......................................................................... 2-13
Zero correct ....................................................................... 2-14
SCPI programming - zero check and zero correct .......... 2-15
A) SYSTem:ZCORrect:ACQuire ............................... 2-15
B) SYSTem:ZCORrect[:STATe] <b> ........................ 2-16
Measurement considerations .................................................... 2-16
3 Measurements
Measurement overview ............................................................... 3-2
Procedure ............................................................................. 3-2
Step 1. Enable zero check ............................................ 3-3
Step 2. Perform zero correction ................................... 3-3
Step 3. Select a manual measurement range
or enable auto range ..................................................... 3-3
Step 4. Connect the current to be measured to
the picoammeter ........................................................... 3-3
Step 5. Disable zero check and take a reading
from the display ........................................................... 3-3