Cooper Instruments & Systems LTL 730 Wireless Tension Link Load Cell - Manual (Page 27)

CF 150 LTL 730 24 12/08
Problem Possible Cause Solution
system straight. Verify system is applying force directly through the
dynamometer with no off center or torsional loads being applied
to the instrument.
Local gravitational
variances If being compared against dead-weights, check your local
gravitational constant (see Force Measurement & Weighing
Differences section). Use custom units to compensate or
calibrate on-site.
Check repeatability Place LTL 730 in low-resolution mode. Lift an arbitrary weight
several times as close to capacity as possible. Record each
weight reading. Do the readings differ from each other?
Calculate the standard deviation of the readings using a
spreadsheet such as Microsoft Excel. See if the deviation is
greater than 0.1% of the instrument capacity.
appear accurate
Compare against a
reference load. Place LTL 730 in low-resolution mode. Apply a known load near
instrument capacity. Check calibration date.
Low batteries.
Distance is excessive
or dead-radio pocket Bring remote closer to dynamometer. Allow several seconds to
retrain. Radio
communication
intermittent
Excessive radio noise
or interference in
environment Remove dynamometer and remote from the environment.
Attempt communications in an area free of local radio signals.
Dead batteries.
Distance is excessive,
dead radio pocket Bring remote closer to dynamometer. Allow several seconds to
retrain.
Radio systems
initialized. No “Y”
appears Enable the radio system in the COM2 configuration of both
instruments (under Comm menu).
Displayed Change batteries in the device when the is blinking
Operating channels
matched Remote and link must be on the same operating channel. See
LTL 730 and Communicator configurations of COM2 for radio
(under Comm menu).
Radio
communications not
working at all
Excessive radio noise
or interference in
environment Remove dynamometer and remote from the environment.
Attempt communications in an area free of local radio signals.
See Radio Information section of the manual.
Remote reading
changes to dashes Low batteries, lost
communications See steps above for improving communications.
Display locks up on
marquee Poor connection
between LTL 730 and
Communicator Remove batteries from LTL 730 and Communicator, replace
them and power up.
14.0 WEIGHING AND FORCE MEASUREMENT PRACTICE
The basis for all electronic force measurement or weighing is measurement of stress in a
load cell body. To obtain optimal results it is necessary to establish a few basic rules;
otherwise the effect may be a nonlinear or nonrepeatable response. Read and follow
these tips and see the illustrations on the next page.
14.1 Load Centering
For accurate performance the force acting on the unit must be in line with the unit.
Centering the load is accomplished by using the shims on each side of the load cell so
that it is centered on the shackle pin. See the illustration at right. The 50,000 lbf (20000
kgf) and higher LTL 730s also include spacers supplied with shackles.