MTS Series 793 - Manual (Page 156)

MTS Series 793 Tuning and Calibration
Force Sensor Calibration
Calibration Procedures 156
Force Sensor Calibration
A force sensor (also called a load cell) is calibrated with a load standard. A load
standard can be a special calibrated force sensor with its own electronics or a set
of calibrated dead weights. A force sensor is calibrated such that the maximum
compression and tension represent ±100% of the full-scale capacity of the sensor,
with zero force set at midcapacity.
Prerequisites Be sure the items described in “Pre-Calibration Considerations” on page 123 are
true.
A force sensor requires DC excitation, which requires either a dedicated DC
conditioner or a digital universal conditioner (DUC) configured in the DC mode.
You must know which conditioner is connected to the force sensor.
Initial calibration
If you are calibrating a sensor for the first time, you may find it necessary to:
• Perform an initial tuning of the sensor channel before calibration.
• Perform the procedure twice.
Recalibration
If you are recalibrating a sensor, use the existing calibration values as a starting
point.
Considerations for full-
range conditioners
Full-range conditioners allow you to choose Gain/Delta K or Gain/Linearization
for calibrating force conditioners. The mV/V Pos Tension and mV/V Pos Comp
calibration types are typically not used for controllers equipped with full-range
conditioners.
• During calibration, Manual Offset should always be set to zero.
• During calibration, ensure that Electrical Zero Lock is checked on the
Offset/Zero tab of the Inputs panel.
• After calibration, do not change the electrical zero adjustment.
Readjustment of electrical zero after calibration will change the point at
which linearization takes place, disturbing other calibration settings
(especially Delta
K).