LINK Systems System 1100 Tonnage Monitor - Manual (Page 74)

CALIBRATION
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6-2
located under the machine slide. Where multiple load cells or
jacks are employed for calibration, they should be located in a
geometrically symmetrical pattern with respect to the center of the
machine slide. The preferred procedure is to place a single load
cell or jack directly under each connection to the slide from
crankshaft, hydraulic cylinder, etc., on overdriven machines.
When multiple load cells are used, each load cell should be of the
same physical dimensions and load rating. The load cells must be
shimmed as necessary to provide equal loads on each cell. The
combination of geometrically symmetrical location and equal loading
for load cells will produce a total machine load equal to the sum
of the loads on each individual load cell and will simulate a
single central load.
Note! Incorrect gib adjustments, and/or severe bearing wear in the
slide drive system can cause the slide to cock and generate
significant forces against linear guides or gibs. These
non-symmetrical forces can void the assumption of central loading
and introduce some error in the calibration procedure.
CAUTION! Extreme care should be used in calibration procedures for
tonnage monitors. Severe damage to the machine being calibrated or
the calibration equipment can result from incorrect shut height
adjustments, etc., on machines driven by rotary crankshafts, or
from any action that causes a machine to develop excessive forces.
Injury to personnel calibrating the machine or to others in the
machine area can result from poorly implemented load cell or
hydraulic jack stacks that fly out of the machine under load.
NEVER place hands between load cell or hydraulic jack stacks and
the machine slide! Link Systems provides calibration services at
a reasonable charge. These services should be used if there is
doubt that customer employees can correctly and safely calibrate a
machine.
6.1 Dynamic Calibration with Load Cells
1) Check to see that the System 1100 Tonnage Monitor for
permanent use on the machine is installed as per the
installation instructions of this manual.
2) Turn on the power to the System 1100 Tonnage Monitor. Observe
that the System 1100 tonnage displays zero. If the tonnage
displays fail to zero within 40 seconds or an error occurs,