EasyManuals Logo

BRUEL & KJAER 4220 User Manual

BRUEL & KJAER 4220
28 pages
To Next Page IconTo Next Page
To Next Page IconTo Next Page
To Previous Page IconTo Previous Page
To Previous Page IconTo Previous Page
Page #11 background imageLoading...
Page #11 background image
fection
of
the
specially
shaped
cam
which
can
be
considered
as
of
a
rather
perfect
sinusoidal
shape,
but
by
the
wear
of
the
piston
tips
sliding
on
the
cam.
During
experiments
it
has
been
noticed
that
the
tips,
if
no
special
care
has
been
taken,
can
become
worn
on
one
side,
and
in
due
course
slightly
distort
the
movement
of
the
pistons.
The
pistons
are
made
of
a
special
synthetic
material,
presenting
a
particularly
low
friction
coefficient
with
steel.
The
cam
and
pistons
are
lubricated
with
high
quality
oil. Also,
the
tension
of
the
retaining
spring
is
carefully
adjusted
to
maintain
even
contact
of
the
piston
tips
on
the
cam,
without
excessive
pressure.
By
means
of
these
precautions,
the
distortion
factor
of
the
Piston-
phone
is
maintained
lower
than
3 %
at
250 Hz.
The
frequency
spectrum
of
the
signal
produced
by
the
pistonphone
is
shown
in
Fig. 6 .
.
~
o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o. o o o
·o
o o o o o 1
~6~ ~·~
~·~
Odb
"
10
100
1000
10
000
cjs
loOS79
Fig. 6.
Typical
frequency
spectrum
of
the
Pistonphone
recorded
by
means
of
the
B & K
Spectrum
Recorder
Type
9312.
The
spectrum
shows
a
second
harmonic
of
1.8
%,
and
some
noise
caused
in
the
coupler
by
the
motor,
around
7ooo Hz.
Coupler
and
Adaptors.
The
coupler
cavity
of
the
Pistonphone
4220
has
been
designed
with
dimen-
sions
which
are
small
with
respect
to
the
wave-length
of
the
sound,
in
the
frequency
range
involved.
The
coupler
has
an
opening
diameter
of
23.8
mm,
fitting
microphones
with
a
standard
diameter
of
o.936
inch
(as
specified
in
A.S.A. Z 24-8-1949)
such
as
the
Types
B & K 4131
and
4132,
W.
E. 640
AA,
MR 103.
9

Table of Contents

Questions and Answers:

Question and Answer IconNeed help?

Do you have a question about the BRUEL & KJAER 4220 and is the answer not in the manual?

BRUEL & KJAER 4220 Specifications

General IconGeneral
BrandBRUEL & KJAER
Model4220
CategoryMeasuring Instruments
LanguageEnglish

Related product manuals