Checking The Sensitivity Of Counters - Fluke PM 6666 Operator's Manual

Page: 44
Low Impedance Inputs (50Ω)
If You Have a Calibrated Signal Source
–
Adjust the signal-source to the sensitivity limit of the
counter.
–
Connect it directly to the input of the counter.
–
Check that the counter is operating correctly.
If You Don't Have a Calibrated Signal Source
Use either of the following methods
Method 1
–
Connect the output of the signal-source directly to the in-
put of the counter.
–
Turn off AUTO and Set the counter to maximum sensitiv-
ity (if adjustable).
–
Adjust the amplitude of the signal-source to the minimum
level accepted by the counter.
PM 6666 - OPERATORS MANUAL
APPENDIX 1
–
Disconnect the cable from the counter and connect it to
the oscilloscope.
–
Read the amplitude on the oscilloscope.
–
Check that the reading is the same as, or less than, the
sensitivity level in the counter specifications.
Method 2
–
Connect the signal-source to the oscilloscope.
–
Adjust the output amplitude of the signal-source until the
oscilloscope indicates the sensitivity limit in the counter
specifications.
–
Disconnect the cable from the oscilloscope and connect
it to the counter.
–
Turn off AUTO and set the counter to maximum sensitiv-
ity (if adjustable).
–
Check that the counter is operating correctly.
These procedures ensure unambiguous measurements of
the signal voltage at the input of the counter.