Dytran 1051C User manual

Dynamic Transducers and Systems
21592 Marilla St. • Chatsworth, CA 91311 • Phone [phone]
www.dytran.com • e-mail: [email protected]
OG1051C.DOC 12-20-00
Rev A, ECN 9708, 03/06/13
Rev B, ECN 12897, 08/18/16
OPERATING GUIDE
MODEL 1051C
CHARGE MODE DYNAMIC FORCE SENSOR
This manual contains:
1) Outline/Installation drawing 127-1051C
2) Operating Instructions Model 1051C

Rev B, ECN 12
INTROD
U
T
measure
c
dynamic
r
Lbs full s
c
(quasi st
a
500 Lbs f
u
T
high prel
o
dynamic
f
negative-
g
for tensio
n
M
bottom a
n
surface a
n
connecto
r
DESCRI
P
R
cross sec
S
connecto
r
top and b
o
Figur
e
M
where ra
d
drop sho
c
instrume
n
machiner
y
around th
exit radial
R
member
(
evenly ac
897, 08/18/16
U
CTION
he 1051C fo
r
c
ompressive
r
ange, e.g., f
r
c
ale over a v
e
a
tic to 50 kHz
.
u
ll scale in te
hin x-cut qua
o
ad, provide
a
f
orce inputs.
T
g
oing for co
m
n
.
M
odel 1051C
f
n
d top surfac
e
n
d load or im
r
.
P
TION
R
efer to figure
tion of Model
eries 1051C
r
and tapped
o
ttom for stu
d
e
1: CROSS
M
odel 1051C
i
d
ial space is
n
c
k application
n
t is also use
d
y
shafts or p
u
e machine fo
ly.
R
eferring to Fi
(
called the pl
a
ross the qua
r
O
P
C
H
r
ce sensor is
d
and tensile f
o
om 10 Lbs fu
e
ry wide freq
u
.
) This senso
r
nsion.
rtz crystals h
e
a
charge out
p
T
he output p
o
m
pression an
d
f
eatures tapp
e
s for attach
m
pact cap and
1 below for
a
Series 1051
C
has a transv
e
1/4-28 x .17
5
d
mounting.
SECTION,
M
i
s recommen
d
n
ot limited su
c
s and for ge
n
d
to monitor f
o
u
shrods wher
e
r the electric
a
gure 1, the u
p
a
ten) distribu
t
r
tz crystals w
h
PL
A
QU
A
CR
Y
BA
S
MO
U
SU
R
10-
3
CO
N
P
ERATING I
N
H
ARGE MO
D
d
esigned to
o
rces over a
w
ll scale to 50
0
u
ency range,
r
can measu
r
e
ld under ve
r
p
ut analogou
s
o
larity is
d
positive-goi
n
ed holes at t
h
m
ent to test
a radial 10-
3
a
representat
i
C
force sens
o
e
rse mounte
d
5
deep holes
a
M
ODEL 1051
C
d
ed for use
c
h as in som
e
n
eral use. Thi
s
o
rces in
e
there is sp
a
a
l connector
t
p
per threade
d
t
es the force
h
ile sealing t
h
A
TEN
A
RT
Z
Y
STALS
S
E
U
NTING
R
FACE
3
2
N
NECTOR
N
STRUCTIO
D
E DYNAMI
C
w
ide
0
0
r
e to
r
y
s
to
n
g
h
e
3
2
i
ve
o
r.
d
a
t
C
e
s
a
ce
t
o
d
h
e
i
T
s
r
n
i
s
d
T
c
g
f
A
r
F
S
t
c
t
a
d
i
a
a
t
b
NS MODEL
1
C
FORCE SE
N
i
nstrument a
g
T
he very thin
s
mall portion
r
esults in a v
e
n
atural frequ
e
i
nstrument is
s
teel of simil
a
Refe
r
127-1051C,
s
d
imensioned
T
HEORY OF
Forc
e
c
rystals caus
g
enerated, w
f
orce.
A
spe
c
A
mplifier bec
a
r
ead out this
c
F
igure 2: TH
S
CHEMATI
C
A
ch
a
t
he very sma
l
c
hanging the
t
he charge m
a
low imped
a
d
irectly to al
m
A
ch
a
i
nput impeda
n
a
nd with cap
a
a
s the gain o
f
t
he transfer f
u
b
ecomes:
1
051C
N
SOR
g
ainst moistu
r
quartz cryst
a
of the length
e
ry high stiffn
e
ncy. The ov
e
almost com
p
a
r dimension.
r
to the Outli
n
s
upplied with
outline of M
o
OPERATIO
N
e
compressin
ing an electr
o
hich is exactl
y
c
ial type of a
m
a
use of its hi
g
c
harge. Refe
E CHARGE
A
C
a
rge amplifie
r
l
l signal from
signal. The
c
ode signal g
e
a
nce voltage
w
m
ost any type
a
rge amplifie
r
n
ce-inverting
a
citive feedb
a
f
the amplifie
r
u
nction of th
e
r
e and other
c
a
ls comprise
a
of the senso
r
ess and high
e
rall stiffness
p
arable to a s
o
n
e/Installatio
n
this manual,
f
o
del 1051C.
N
g the load ce
o
static charg
e
y
analogous
t
m
plifier called
g
h impedanc
e
r to Figure 2
b
A
MPLIFIER,
r
has the abili
the force se
n
c
harge amplif
i
e
nerated by t
h
w
hich may th
e
of readout i
n
r
is essentiall
y
amplifier wit
h
a
ck. It can be
r
(-
A
) approa
c
e
charge amp
l
2
c
ontaminants
a
relatively
r
which
rigidity and
of this
o
lid piece of
n
drawing,
f
or a
ll stresses th
e
e
to be
t
o the applie
d
a Charge
e
level must
b
elow.
SIMPLIFIED
ty to read ou
t
n
sor without
i
er converts
h
e crystals to
e
n be fed
n
strument.
y
a very high
h
infinite gain
shown that
c
hes infinity,
l
ifier
2
s
.
e
d
t

Rev B, ECN 12897, 08/18/16
3
-q
Vo = -------- (Eq 1)
C
f
Where:
V
o is the output voltage (Volts)
q is the input charge, (pC)
C
fis the feedback capacitor, (pF)
This means that the sensitivity of the charge
amplifier is determined by the value of the feedback
capacitor only. Since the output voltage is fed back
to the summing junction of the amplifier (the input
terminal) the virtual input impedance is extremely
high which means that the charge signal generated
by the quartz crystals will not be drained away by
the measuring device.
SIGNAL POLARITY
Compressive forces on these sensors (see
Figure 1) produce negative-going output signals.
This is because most charge amplifiers are inverting
amplifiers and the output signal from the charge
amplifier will be positive going for compressive
loads. This is conventional.
By the same token, tension loads on the
1051C will produce positive-going output signals.
SENSITIVITY
The nominal charge sensitivity of Model
1051C is -18 pC/Lb.
CHARGE AMPLIFIER SELECTION
Dytran manufactures many different types of
charge amplifiers to suit the needs of most any
measurement requirement from the larger laboratory
type Model 4165 which features ranging and filtering
plus standardization to the miniature in-line types
4751 and 4705 which adapt the 1051C to LIVM
operation with constant current power units.
For laboratory measurements, the 4165 is
recommended and for field use, the dedicated
sensitivity n-line charge amplifiers may be a better
choice.
Consult the factory for recommendations on
the best type of charge amplifier for your
measurement needs.
INSTALLATION
Refer to outline/installation drawing 127-
1051C, supplied with this guide.
To mount model 1051C, it is necessary to
prepare a flat smooth mounting surface of 5/8”
minimum diameter. The surface should be flat to
.0005 TIR for best results.
The surrounding area must provide for room
to connect the cable to the 10-32 connector at the
end of the radial connector housing. Drill and tap a
1/4-28 hole to accept the model 6204 1/4-28
mounting stud. Thread in the mounting stud
(supplied) to secure the 1051C to its mounting
surface.
Before mounting the 1051C, thread the
sensor into the mounting port and examine the fit of
the mounting surfaces. They must meet parallel, i.e.,
a wedge must not be formed between these
surfaces. Also, at this time, inspect the mating
surfaces for foreign particles, which may become
lodged between these surfaces and clean if
necessary. It is important that the mating surfaces
meet squarely and intimately with no particles of
foreign matter of any kind included between them.
Foreign particles included between mating surfaces
could damage the sensor and/or modify the
sensitivity of the sensor.
When you are satisfied that the surfaces are
square and clean, place a thin layer of silicone
grease on one of the surfaces and thread the force
sensor place, torquing it in place with 25 to 30 Lb-
inches of torque to secure.
For most impact applications, the Model
6210S (steel) impact cap will be utilized. This cap is
threaded into the platen (top surface of the force
sensor). Thread this cap securely into the tapped
hole in the platen, again inspecting for foreign
particles between mating surfaces and clean if
necessary. For more permanent installations,
thread-locking compounds may be used to secure
the installation. Use these compounds sparingly.
For a slightly higher resonant frequency, the
aluminum cap, Model 6210A, may be a better choice
in some applications.
Connect the sensor to the charge amplifier
using Series 6010AXX cable (10-32 to 10-32) or
Series 6011AXX (10-32 to BNC plug), depending on
the connector called for by the power unit. Tighten

Rev B, ECN 12897, 08/18/16
4
the cable lock ring snugly by hand. Do not use a
pliers or vise grips on these cable lock rings.
OPERATION
After connecting the cable from the sensor
to the charge amplifier, if the charge amplifier is the
laboratory type, press the reset button which should
zero the output voltage. You are now ready to select
your range, set the discharge time constant and
make the measurement.
If you are using an in-line charge amplifier,
there is no reset button so you must wait a few
seconds for the output voltage to stabilize. The
instrument may be used before complete
stabilization of the sensor bias voltage since the DC
bias is blocked within the power unit.
Consult the factory for the low frequency
limitations and other limitations when using the in-
line charge amplifiers.
LOADING CONSIDERATIONS, IMPACT
When applying loads to the force sensor, it
is important to note that the load must be distributed
evenly across the force sensitive face of the force
sensor.
For impact measurements, the impact cap
accomplishes this adequately in most cases. During
impact testing, try to control the impact point so the
contact occurs close to the center of the sensor. For
more massive objects impacting the sensor, a
special thicker cap may need to be employed.
Consult the factory for special applications such as
this.
Remember also, that the impact caps may
be supplied in a variety of materials to suit the exact
needs of the measurement. Call the factory to ask
about the many different materials available, on
special order, to meet your needs.
FIGURE 3
ILLUSTRATING OFF-CENTER LOADING
Figure 3 is intended to illustrate the right and
the wrong way to apply loads to the 1051C.
Obviously we cannot address the many different
applications but we merely want to illustrate, in the
most basic sense, the proper and improper ways to
apply loads to these instruments for the purpose of
heading off measurement problems which may be
incurred by improper use.
In the illustration chosen in Figure 3, a
hydraulic or pneumatic ram is loading the force
sensor dynamically. It is important that the force be
evenly distributed, centrally, to the force sensor and
the right way would be to use a steel ball to evenly
load the sensor through a special adaptor which has
been designed to center the ball over the force
sensor.
Dytran offers such adaptors as a special
order accessory. Our engineering department and
our state of the art machine shop are at your
disposal for the design and fabrication of such
adaptors. Call the factory for assistance with your
particular measurement problem.
TENSILE LOADING
Figure 4 illustrates one proper way to load
the 1051C in tension. Again, the forces must travel
through the center of the sensor.
STEEL BALL
SPECIAL
ADAPTOR
RIGHT
CENTRAL LOADING
WRONG
OFF-CENTER LOADING
FF

Rev B, ECN 12897, 08/18/16
5
FIGURE 4
PROPER TENSILE LOADING
The arrangement shown in Figure 4 ensures
that the load is applied centrally to the sensor
without bending moments and transverse loading.
One important point to keep in mind when
making tensile measurements is that, due to limits in
the design of the internal preload structure of these
sensors, the maximum tensile force is limited to
500 Lbs. in this series. If this level is exceeded,
the sensor may be destroyed and the load will be
suddenly released. This could engender dangerous
situations for personnel and equipment if this
eventuality is not fully understood.
Remember that the maximum force is the
combination of both static and dynamic tensile
forces. For example, if the sensor is supporting a
static load of 250 Lbs., the maximum dynamic range
possible is 250 Lbs, (500 - 250).
QUASI-STATIC CONSIDERATIONS
Close to DC measurements are possible
with the 1051C when used with a laboratory type
charge amplifier such as the model 4165. These
force sensors are calibrated at the factory by placing
a traceable compressive force on them, (with a
proving ring) then rapidly removing it and capturing
the resultant step function on a digital storage
oscilloscope. This is a very accurate and repeatable
method for calibration of these sensors.
MAINTENANCE AND REPAIR
The sealed construction of model 1051C
precludes field maintenance. Should you experience
a problem with your sensor, contact the factory to
discuss the problem with one of our sales engineers.
If the instrument must be returned to the factory, you
will be issued a Returned Materials Authorization
(RMA) number so we may better follow the
instrument through the evaluation process. Please
do not return an instrument without first obtaining the
RMA number. There is no charge for the evaluation
and you will be notified of any charges before we
proceed with a repair.
PROPER TENSILE LOADING
USING THREADED HOOK EYES
F