Model 493.02 Controller Service
Calibrating an LVDT
Calibration
114
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 119
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.
The Total Gain value is calculated by multiplying the Pre-Amp and
Post-Amp gain values. If the total desired gain amount is known (from
a calibration sheet), you can enter the amount in the Total Gain box
and the software will calculate the Pre-Amp and Post-Amp gain
values automatically.
When you are calibrating an AC conditioner, use the Post-Amp gain
control to increase gain. If more gain is needed, you must disable
mechanical input
Indicated output
∆K > 1
∆K = 1
∆K <
Gain