Kaman KD-2306 - Manual (Page 13)

Kaman Precision Products PART NO: 860512-001
www.kamansensors.com Last Revised: 8/3/2009
13
5. Reposition the target to minimum displacement (i.e. offset) and adjust the MID (Gain)
controls until output reads the desired negative output voltage.
6. Reposition the target to full-scale displacement, plus offset. Read the output voltage and
note the difference between the actual reading and the desired reading. Adjust the MAX
(Linearity) controls until the output reads the desired voltage level, then continue past the
desired reading by an amount equal to the first difference you noted. This technique is
called 100% oversetting and is used to reduce the number of iterations needed to calibrate
the system.
7. Repeat Steps 4 through 6 as many times as necessary until the desired output voltage at
each point obtained without additional adjustment.
4.3.4 Alternate Bipolar Voltage Output Calibration
You may not be able to achieve maximum sensitivity using this technique. This method may be
preferred if the maximum voltage does not exceed +10 VDC.
1. Use the Full-Scale procedure in section 4.3.1 to calibrate the system initially from 0 VDC to
the desired maximum.
2. Position the target at mid-scale and adjust the MIN (Zero) control counterclockwise until
output reads 0 VDC.
3. Check the two ends, the points closest and farthest from the sensor, to verify they equal
minus and plus one half of the original full-scale output voltage. For example, if your original
full-scale voltage was 0-4 VDC, it should now be -2 to +2.
In theory, adjusting the (MID) Zero controls in this technique should not affect sensitivity or linearity.
In practice, however, you may see a very slight change indicated by voltage readings other than
minus and plus one-half full scale. You may then choose to use the primary bipolar technique to fine-
tune the calibration.
4.3.5 High Accuracy Band Voltage Calibration
DISPLACEMENT
offset
VDC
0
High Accuracy Band
Calibration
CALIBRATED
RANGE
This procedure is used to monitor changes in position that are less than the specified linear
measuring range of your sensor, or when you are interested in increased accuracy over a smaller
range and not concerned about high accuracy outside of that range.