Keithley 6485 User Manual

Model 6485 Picoammeter Instruction Manual Limit Tests 8-3
The 2-stage limit testing process is shown in Figure 8-3. If limit 1 fails, the L1 message is
displayed and the test is finished. Limit 2 is not tested because the pass band relationship
between the two stages implies that if limit 1 fails, limit 2 must also fail. If limit 1 passes,
the limit 2 test is performed. If limit 2 fails, the L2 message is displayed. If both limit 1
and limit 2 pass, the OK message is displayed. The display messages for limit tests are
summarized in Table 8-1.
A test is only performed if it is enabled. Therefore, you can perform a single-stage test or a
2-stage test. In the flowchart (Figure 8-3), operation simply proceeds through a disabled
test.
Table 8-1
Test limit display messages
Display
Message
Limit 1
Test Result
Limit 2
Test Result
:OK Pass Pass
:L1 Fail Not Performed
:L2 Pass Fail

Keithley 6485 Specifications

General

Model	Keithley 6485
Category	Picoammeter
Input Impedance	>10^14 Ohms
Voltage Burden	<200µV
Accuracy	0.4% of reading
Voltage Source Range	Not Applicable
Voltage Source Resolution	Not Applicable
Voltage Source Accuracy	Not Applicable
Interface	IEEE-488
Power Requirements	100V to 240V AC, 50/60Hz
Dimensions	89 mm high x 214 mm wide x 369 mm deep (3.5 in x 8.4 in x 14.5 in)