DigiVIT User Manual - Kaman Precision | Position sensors

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4.1 Volt Out SetupThis option allows selection of the voltage output range from the system.The actual voltage will go 1% above or below the voltage output range selected if the sensor isabove or below the calibrated range.4.2 mA Out SetupThis option allows selection of the current output range from the system.The actual current will go 5% above or below the current output range selected if the sensor isabove or below the calibrated range. In the case of 0-20mA output, it will not go below zero.4.3 Cal SetupThis selection allows linearization calibration and temperature compensation. With theexception of the 2 Pt. or 3 Pt. Adjust (reference 4.8) all other calibration methods will zero outthe temperature compensation coefficients and any offset.4.4 Linearization Options3 options are available for linearization calibration, 2 point, 6 point and 21 point.Note: Performing a linearization calibration after a temperature compensation calibration willvoid the temperature compensation calibration. All linearization calibrations begin by locatingthe sensor at the maximum distance it will be from the target during operation. This is typicallythe sum of the offset distance and full scale range.4.4.1 2 Pt. CalThe 2 point calibration is useful if either linearity of the output is not a concern or if the sensor isoperated over a very short range. Ranges less than 10% of the standard range (a standardrange is normally 33% of the sensor diameter) typically will result in good linearity. For rangesbelow 5% of the standard range; this is the recommended method.To perform a 2 Pt calibration, the sensor needs to be position at MAX distance from the sensorface (i.e. full scale) so that it can optimize for a given sensor. After that, the sensor needs to bepositioned at only the offset (MIN) and full range (MAX) positions.Note: Any previous temperature compensation calibration will be voided when a 2 Pt. calibrationis performed.www.kaman<strong>sensors</strong>.com PART NO: 860525-001Last Revised 9/16/2013- 8 -
4.4.2 6 Pt. Poly CalThe 6 point polynomial cal fits a 5th order polynomial through the data points to linearize thesensor output. In most cases this method works very well though there can be exceptions.The sensor needs to be position at MAX distance from the sensor face (i.e. full scale) so that itcan optimize for a given sensor. After that the sensor needs to be position at offset (MIN) andthen at 20%, 40%, 60%, 80%, and 100% of the range to complete the calibration.Note: Any previous temperature compensation calibration will be voided when a 6 Pt. calibrationis performed.4.4.3 21 Pt. Pcws CalThis calibration will result in the best performance. It is a 21 point piecewise linearizationmethod. This option works best if the curve is too oddly shaped for a polynomial to fit well.The sensor needs to be positioned at the MAX distance from the sensor face (i.e. full scale) sothat it can optimize for a given sensor. After that, it needs to be positioned in 5% of the rangeincrements from 0-100%.Note: Any previous temperature compensation calibration will be voided when a 21 Pt.calibration is performed.4.5 Temperature CompensationThe digiVIT optimizes the sensor for temperature stability and linearity using proprietaryalgorithms. However, even with this optimization, some residual error exists due totemperature. Temperature stability can generally be improved by a factor of 5-10 usingadditional steps to temperature compensate the unit. To perform temperature compensation,data from 2 different displacements with 2 different temperatures must be acquired by the unit.The actual displacement does not matter, but the recommended displacements areaproximately10% and 90% of the calibrated range. If the best temperature coefficient is desiredat a particular displacement, that displacement should be chosen as one of the displacementsused. The temperature compensation algorithm will have the smallest temperature error at thatdisplacement 1 and 2 when the calibration is completed. The 4 required points are:D1T1 (Displacement 1, Temperature 1)D1T2 (Displacement 1, Temperature 2)D2T1 (Displacement 2, Temperature 1)D2T2 (Displacement 2, Temperature 2)The temperature compensation calibration menu controls the order of the 4 points.www.kaman<strong>sensors</strong>.com PART NO: 860525-001Last Revised 9/16/2013- 9 -
Page 1 and 2: Non-contact Displacement MeasuringS
Page 3 and 4: 6.3 2-Point Linear Calibration ....
Page 5 and 6: PART 2 - CONNECTIONSThe digiVIT I/O
Page 7: PART 4 - MENU TREEThe menu tree for
Page 11 and 12: slightly depending on the sample ra
Page 13 and 14: PART 5 - ETHERNET OUTPUTThe digiVIT
Page 15 and 16: PART 6 - CALIBRATION EXAMPLES6.1 Ge
Page 17 and 18: 2) Position the micrometer at the d
Page 19 and 20: 6.6 2-Point AdjustmentNote: A 2 poi
Page 23 and 24: CommandSystemPasslevelRequiredParam
Page 25 and 26: Characterized with an aluminum targ
Page 27 and 28: APPENDIX D: CALIBRATION EXAMPLES VI
Page 29 and 30: D.4 - 2 Point Adjustment1) Position
Page 31 and 32: APPENDIX E: DIMENSIONSDimensions in
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DigiVIT User Manual - Kaman Precision | Position sensors

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