Kaman Extreme Environment Sensors - Manual (Page 16)

High Temperature Displacement System
Calibration Procedure
All the sensors were calibrated at Kaman Instrumentation using a flat or curved
target either specified or furnished by the customer. The target thickness is a
minimum of 12.7 mm (.50 inches). Calibration of the sensors was optimized at 25oC
(77oF using the mounting geometry described in appendix C.
The following procedure (using suitable micrometers or their equivalent to vary the
spacing from the sensor to target) is used for adjustment of the transducer.
Adjustments should be made only if deemed absolutely necessary, since for most
target materials, the thermal compensation is influenced by the linearity control.
Step 1 With the target at "zero" displacement (at the recommended or
desired offset from the face of the transducer) adjust the ZERO
control until the output reads zero volts (i.e. 0 mV for .25mm (.01
inches) for the standard 1975 sensor).
Step 2 Move the target away from the transducer to the displacement
equal to half the full range (plus offset). Adjust the GAIN control to
obtain a half-scale voltage reading at the output (i.e. for the
standard 1975 system 1000 mV for 2.75mm (.11 inches) for
nonmagnetic targets).
Step 3 Move the target to the full range displacement point (plus offset)
and adjust the LINEARITY (coarse or fine) control to the full scale
output (i.e. for the standard 1975 system 2000 mV at 5.33mm (.21
inches) for nonmagnetic targets).
Step 4 Repeat Steps 1 through 3 until the best linearity is obtained.
See the 7200 or 8200 general instruction manual for other methods of calibration.
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