MTS Series 793 - Manual (Page 142)

MTS Series 793 Tuning and Calibration
Displacement Sensor Calibration
Calibration Procedures 142
Task 6 Gain/Delta K Calibration
If you using Gain/Delta-K for your calibration type, complete the following
procedure. If not, complete Task 7 Gain/Linearization Calibration on page
147
Calibrate actuator
retraction
LVDTs can be calibrated so that a positive output represents actuator extension
and a negative output represents actuator retraction, or vice versa.
You calibrate the negative side of the output with gain and the positive side of the
output with Delta K.
Delta K compensates for differences in symmetry between the positive and
negative outputs.
You should calibrate actuator extension at 80% of the full scale range.
Gain controls
Pre-Amp gain is a selectable gain amplifier with predefined values. Since
changes in Pre-Amp gain can cause spikes in the feedback signal, Pre-Amp gain
can only be adjusted when hydraulics are off.
Post-Amp gain is a finer, operator-defined gain control that can be adjusted
when hydraulics are on.
mechanical input
Indicated output
Δ K > 1 Δ K = 1
Δ K < 1
Gain