KDM-8206
Non-Contact Displacement Measuring
System User’s Manual
This apparatus, when installed and operated per the manufacturer’s recommendations,
conforms with the protection requirements of EC Council Directive 89/336/EEC on the
approximation of the laws of the member states relating to Electromagnetic Compatibility. Refer
to the KMD-8206 Declaration of Conformity or contact Kaman Measuring Systems for details.
Copyright © 2011 Kaman Precision Products
PART NO: 860516-001 A Division of Kaman Aerospace Corporation
Last Revised: 6/20/2011 Measuring Systems
217 Smith Street
Middletown, CT 06457
www.kamansensors.com
Table of Contents
PART 1 – KDM-8206 DESCRIPTION....................................................................................................3
PART 2 – CONNECTING THE KDM-8206............................................................................................5
PART 3 – KDM-8206 OUTPUTS...........................................................................................................7
3.1 ANALOG VOLTAGE OUTPUT: ...........................................................................................................7
3.2 4-20 MA CURRENT OUTPUT: ..........................................................................................................7
3.3 DEMODULATOR OUTPUT:................................................................................................................7
3.4 DIFFERENTIAL (BALANCED) OUTPUT: ..............................................................................................8
PART 4 – CALIBRATING THE KDM-8206...........................................................................................9
4.1 CALIBRATION CONTROLS................................................................................................................9
4.1.1 MIN CONTROLS ..........................................................................................................................9
4.1.2 MID CONTROLS ........................................................................................................................10
4.1.3 MAX CONTROLS.......................................................................................................................10
4.2 CALIBRATION METHODS ...............................................................................................................11
4.3 CALIBRATION PROCEDURES .........................................................................................................12
4.3.1 FULL SCALE CALIBRATION PROCEDURE (VOLTAGE)....................................................................12
4.3.2 FULL SCALE CALIBRATION PROCEDURE (CURRENT) ...................................................................13
4.3.3 BIPOLAR VOLTAGE OUTPUT CALIBRATION PROCEDURE ..............................................................14
4.3.4 ALTERNATE BIPOLAR VOLTAGE OUTPUT CALIBRATION................................................................15
4.3.5 HIGH ACCURACY BAND VOLTAGE CALIBRATION..........................................................................16
PART 5 – SYNCHRONIZING MULTIPLE MEASURING CHANNELS...............................................17
PART 6 – SYSTEM MODIFICATIONS................................................................................................18
6.1 TEMPERATURE COMPENSATION....................................................................................................18
6.2 TARGET MATERIAL.......................................................................................................................18
6.3 SENSOR CABLE LENGTH ..............................................................................................................18
6.4 BRIDGE CARD..............................................................................................................................19
6.5 INTERCHANGEABILITY OF KDM-8200 & KDM-8206 MEASURING MODULES ...................................20
List of Figures
Figure 1 KDM-8206 Circuit...................................................................................................................3
Figure 2 Rear View of KDM-8206 Measuring Module..........................................................................5
Figure 3 J7 Location.............................................................................................................................8
Figure 4 Front View of KDM-8206 Measuring Module.........................................................................9
Figure 5 4-20mA Output Connections................................................................................................13
Figure 6 Bridge Card Location............................................................................................................19
Kaman Precision Products PART NO: 860516-001
www.kamansensors.com
Last Revised: 6/20/2011
2
PART 1 – KDM-8206 DESCRIPTION
Kaman Precision Products’ Model KDM-8206 is a non-contact, linear, analog displacement
measuring system. The system operates on a traditional inductive bridge circuit. This easy-to -use,
versatile system can be utilized for precision static and dynamic measurements of conductive targets.
The sensor coil makes up one or two legs (depending on single or dual coil sensor) of a balanced
bridge network. As the target changes position within the sensor field, the bridge network senses
impedance changes in the sensor coil. These changes are converted to an analog voltage or
current signal directly proportional to target displacement.
Figure 1
KDM-8206 product is a replacement for the KDM-8200 series product and has many improved
features, but uses the same type enclosure and Euro connector. The MIN, MID, and MAX
adjustments were labeled Zero, Gain, and Linearity adjustment controls respectively in the KDM8200 systems.
A KDM-8206 Measuring Module is the signal conditioning electronics unit. It is packaged in a
Eurocard 3U by 7T enclosure.
A KDM-8206 Measuring Channel consists of two subassemblies: a sensor with either an integral
or a removable cable, and a Measuring Module. The Measuring Channel is preconfigured at the
factory for a particular sensor, cable length, target material, and measuring range. The KDM8206 Measuring Channel is a RoHS compliant, CE Marked design. To maintain the CE Mark, the
following precautions are necessary:
1. I/O cable length is limited to a maximum of 30 m (100 ft).
2. The Eurocard electronics are supplied with a cover over to protect the circuit from damage
due to Electrostatic Discharge (ESD). Removal of the cover makes the unit susceptible to
ESD damage and it must be handled accordingly.
The electronics power and I/O must be isolated from the AC Mains and not subject to
3.
transient over-voltages. That is, it must be powered by a D.C. secondary circuit that is
reliably grounded, capacitively- filtered, with peak-to-peak ripple less than 10% of the D.C.
component.
Kaman Precision Products PART NO: 860516-001
www.kamansensors.com
Last Revised: 6/20/2011
KDM-8206 Circuit
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A KDM-8206 Measuring System consists of multiple Measuring Channels installed in a rack
enclosure. The rack typically includes a 110/220 VAC, 50/60 Hz power supply and may also
contain a digital display.
Kaman Precision Products PART NO: 860516-001
www.kamansensors.com
Last Revised: 6/20/2011
4
PART 2 – CONNECTING THE KDM-8206
All input, output, and synchronization connections to the KDM-8206 Measuring Module are at the
terminals of the Euro connector on the rear of the enclosure.
The Measuring Module is designed for insertion in a 3U/84HP rack enclosure. The rack provides
a mating Euro connector and input power supply. The sensor input is via a TBNC connector on
the rear panel of the rack. The output signal is a BNC coaxial connector also on the real panel.
Refer to the separate manual for rack details and operation. A Measuring Channel can be
operated independently of a rack or installed in a user provided rack if connected as detailed in
the table below.
Figure 2
Sensor Return 30 30 Sensor Return
Sensor Inactive Coil 32 32 Sensor Active Coil
Kaman Precision Products PART NO: 860516-001
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Last Revised: 6/20/2011
Rear View of KDM-8206 Measuring Module
KDM-8206 Measuring Module Connections
Function Pin C Pin A Function
+15 VDC in 2 2 +15 VDC in
NC 4 4 NC
- 15 VDC in 6 6 - 15 VDC in
NC 8 8 NC
Ground 10 10 Ground
NC 12 12 NC
V+ Out 14 14 V+ Out
V - Out 16 16 V - Out
NC 18 18 NC
NC 20 20 I Out High
NC 22 22 I Out Low
NC 24 24 Demodulator Out
Ground 26 26 Ground
Synch Out 28 28 Synch In
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All connections in the table are present in a Kaman supplied rack enclosure; no additional wiring must
be specified. Some comments on the connections in this table are as follows:
1. NC = Not Connected
2. Single channel voltage output is between pins A/C 14 and Ground. This is connected to the
upper BNC connector on rear panel of the rack.
3. Differential voltage output is between pins A/C 14 (V+Out) and A/C 16 (V-Out). Output at pins
A/C 16 is not present unless enabled on the Measuring Channel PCB. Refer to section 3.4 of
this manual. V-Out is connected to the lower BNC connector on the rear panel of the rack.
The lower BNC connector is not installed unless differential output is requested.
4. Demodulator output on pin A 24 can be connected to the BNC connector on the rear panel of
the rack in place of V+Out on request. Modification to the channel backplane in the rack is
required.
A good quality linear or switching supply with an output of +15 and -15 VDC is recommended for best
(lowest noise) performance.
Sensor installation recommendations and guidelines are given in Kaman Measuring System’s
Inductive Technology Handbook. A copy of this handbook is available from the website.
Kaman Precision Products PART NO: 860516-001
www.kamansensors.com
Last Revised: 6/20/2011
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