Service manual

6
Frequency Response Measurements
Four channels (Option AY6)
Test up to three devices si mul taneous-
ly with a four-channel 35670A.
Channel one is the common reference
channel and two, three, and four are
the response channels. Alternatively,
select channels one and three as
reference channels for two totally
independent network mea sure ments.
See Option AY6 de scrip tion for more
in for ma tion.
The 35670A has the flexibility to make
measurements of both electrical
networks and me chan i cal devices.
FFT-based network analysis is fast
enough to allow real-time ad just-
ments of circuit pa ram e ters while the
swept-sine option provides exacting
mea sure ments over more than six
fre quen cy decades, and a 130 dB
dynamic range.
Source
Select the optimum stimulus for each
ap pli ca tion—random noise, periodic
chirp, pink noise, fixed sine, burst
random, and burst chirp. For zoomed
network analysis measurements, the
source is band-translated to match
the zoom span at frequencies up to
51.2 kHz. An optional arbitrary source
lets you test your product using real-
world signals. A ±10 Volt DC source
offset facilitates tests of control
systems.
Impact testing
Force and exponential windows allow
impact testing for modal and struc tur-
al analysis. Quality mea sure ments are
ensured using preview and accept/
reject during averaging. A 4 mA
constant current transducer power
supply is built-in for true port a bil i ty.
Limits
Test network measurements against
preset limits. Up to 800 separate line
segments are available for setting
upper and lower limits. Limits are also
used for testing spectrum mea sure-
ments.
Characteristics of a
selected resonance
are automatically
calculated from an
impact mea sure ment
using the fre quen cy
and damping marker.
Limits are used
for go/no go testing
in production. The
response of an
accelerometer is
being checked in
this example.
Markers
A frequency and damping marker
provides the resonant frequency and
the damping ratio of single-degree-
of-freedom frequency response
mea sure ments.
Gain and phase margin markers
extract key frequency-domain stability
data from frequency response mea-
sure ments of control systems.