Agilent Technologies 1153A, Руководство пользователя и обслуживания

Страница: 20 / 38

22
Operating the Probe
Coupling functions
Coupling functions
There are three methods for blocking or compensating for the dc component of a signal.
Each has specific advantages.
Probe system coupling functions
Lf Reject
Lf reject is the best method of eliminating the dc component of a signal when dc is not
a factor in the measurement. Remove the ac adapter if it is installed. The key
characteristics are:
• The low frequency component (from dc to the selected corner frequency) is
automatically nulled by the IF reject circuitry.
• Probe CMRR specifications are not compromised as happens when the ac coupling
adapter is used.
• There is a selectable low frequency corner with -3dB points at 1.7 Hz (LFR1) or 0.14Hz
(LFR2).
• The voltage reject range is ±18 V with the probe alone, ±180 V with the 10:1
attenuator, and ±500 V with the 100:1 attenuator.
With the frequency and voltage characteristics noted elsewhere in this manual, low
frequencies are nulled from the input signal.
dc Offset If Reject ac Coupling Adapter
dc Blocked
Probe alone
Probe with 10:1
Probe with 100:
±18 V
±180 V
±500 V
±18 V
±180 V
±500 V
±200 V
±500 V
±500 V
Set-up needed Adjust offset to put
signal on screen Select If Reject
low-frequency
corner Attach ac Coupling
adapter to differential
probe
Remote Control? Yes
1
Yes
1
No
CMRR
degradation? No No No
Low-frequency
degradation? No Yes Yes
1
Isolated external dc reference and control signals are needed.