Cleveland Motion Controls ULTRA ISC SERIES SLIM CELL TRANSDUCER REV AA - Manual (Page 21)

MAN-70434-0 R EV AA U LTRA ISC S ERIES S LIM C ELL T RANSDUCER
3 P RODUCT A PPLICATION
The Ultra Series Slim Cell Transducer utilizes a twin sensing beam. Conversion from mechanical
strain to an electrical signal is accomplished using semiconductor-based, piezoresistive strain gage
elements. The Full Wheatstone Bridge configuration provides an electrically balanced output
yielding twice the amount of signal swing as half-bridged transducers operated at the same
excitation voltage. Integral span compensation is used to correct for temperature induced gain
changes.
MACHINE FRAME
SLIM CELL TRANSDUCERS
Figure 6- Slim Cell Transducer Incorporating Shaft Bearing Function
Slim Cell Transducers can be used with either rotating (live) shaft rolls (RS type) or, stationary
(dead) shaft rolls (SS type) that incorporate their own low friction bearings. For more information
on transducer type selection refer to Section 4.2.5 .
The Ultra ISC has been developed for those customers who desire to send the transducer signal
directly into their Controller, PLC, PAC, Drive, or Local I/O. When a pair of transducers is used,
the signal outputs can be zeroed, scaled, and summed by software. It is responsibility of the
customer to write this software.
3.1 F INAL CALIBRATION
When calibration is done though application software within the target controller, the greatest
calibration accuracy is achieved though the use of individual gain and offset parameters for each
of the two transducers (which generally are used in pairs). By using separate analog inputs and
separate gain and offset parameters, you can correct for any transfer function differences arising
from subtle mounting variations intrinsic to transducer output variations. If however the loadcells
are summed first and then digitized, the matching of loadcell outputs (as affected by such things as
loadcell orientation relative to the wrap angle) becomes more critical.
The tradeoff between hardware cost and accuracy will impact the decision as to which approach
users decide to take.
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