
Calibration
AutoSet 1500 User Manual
40
Ch 3
1088500
Linearity check
After calibration, you can check linearity to see how accurately tonnage is being recorded
at different loads. Linearity means that AutoSet tonnage readings increase
proportionately to the load. For instance, if AutoSet reads 40 tons with 40 tons on the
load cells, it should read 80 tons with 80 tons on the load cells.
To check linearity, change the load on the press. For instance, if you calibrated at 75%
capacity, reduce the load on the load cells to about 45%. If you calibrated at 50%,
increase the load to about 80%. The tonnage on AutoSet at each strain link should equal
tonnage on the calibration unit at each load cell.
If the tonnages disagree, the problem may be the positioning of your strain links or
twisting forces on the press. Consult your service representative or Data Instruments.
Note, however, that perfect linearity is unachievable. Typically tonnages are 5% to 10%
off at 20-80% of press capacity.