Keithley 486 Instruction Manual page 58

SECTION 3
Front Panel Operation
CAUTION
To prevent damage to the instrument, ad-
here to the following precautions when
floating the input above chassis ground:
1. Do not connect ANALOG OUTPUT LO
to CHASSIS. If there is a ground link in-
stalled at the rear panel binding posts, re-
mote it.
2. Make sure that any monitoring imtru-
ment connected to the analog output is float-
ing.
Paragraph 3.16.8 explains the precautions for
floating measurements in more detail.
Making Current Measurements
Perform the following steps to make current measure-
ments:
1. Turn the instrument on, and allow the Model
486/487 towmupfortwo hours toobtainrated ac-
CUK~Cy.
2. Make sure the instnunent is in the current function
(amps reading displayed). If the V/I ohms function
of the Model 487 is selected kkns reading dis-
played), press SHIFT and then OHM!? to place the in-
strumat back in the current function.
3. Select a current range that is appropriate for the ex-
pected measurement or enable autorange (press
SHIFT and then AUTO RANGE).
4. Enable zero check and, if the display is not zeroed,
perform zero correction by pressing SHIFT and then
CORRECT.
Figure 3-4. Pi
3-9