Kaman KD-2440 - Manual (Page 7)

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KD-2440
Kaman Instrumentation’s Displacement Measuring
System Model KD-2440 is a noncontact linear proximity
measuring system. This low-cost, easy-to-use system
makes precision static and dynamic measurements of
metal targets, and thickness measurements of non-
conductive material backed by metal. The system
includes a switching output that will track RPM
measurement to 10Khz.
Features Summary / Advantages
•••• Outstanding Precision: Static Resolution to 12
Microinches
•••• Easy to Adjust
•••• Excellent Performance with Ferrous Targets
•••• Variable Voltage Input from 12 to 24 Volts DC
•••• Adjustable Gain for up to 22 Volts Output with 24
Volts Input
•••• Compact Rugged Electronics and Sensors
•••• Temperature Tolerant Sensors (to 400°F)
•••• Level Adjustable Switched Output to 10Khz for
Process Control
•••• Drop in Replacement to Kaman’s KD-2400 with
Accessories Kit
KD-2440 Unit
The KD-2440 system consists of three subassemblies:
the sensor with integrated cable, the signal conditioning
electronics module, and the power and output cable.
The KD-2440 electronics uses a standard DB-9
connector to bring +12 Vdc to +24 Vdc into the
electronics and provide outputs for the analog voltage
and switch functions.
5 4 3 2 1
9 8 7 6
I/O Cable DB-9
Connector Face
1 2 3 4 5
6 7 8 9
Electronics DB-9
Connector Face
DB-9 Connections and Power I/O Cable
Color Chart:
Wire Color Pin Signal
1 N/C
BLU 2 SWITCH RX
WHT 3 SWITCH TX
GRN 4 VIN (ALTERNATE)
BLK 5 COMM
6 N/C
RED 7 VIN
8 N/C
ORN 9 VOUT
CLR - CABLE SHIELD
Electronics
The KD-2440 electronics has two potentiometers
accessible through openings in the enclosure for
adjusting the GAIN and SWITCH SET POINT level.
An LED indicates when the optically-isolated switch is in
the closed position. The KD-2440
electronics and sensors utilize SMA type coaxial
connectors: female on the electronics, and male on the
sensor cable. Two production-sensor configurations
are available, the 9C and the 5CM. Data for these two
sensors is shown on the following pages. The sensor
must be attached snugly (finger tight) to the electronics
assembly for the unit to function properly.
Mounting Instructions
Mounting the KD-2440 electronics module can be done
using either of the two holes in the enclosure, and an M-
3 or 4 screw. It is preferable not to remove both screws
from the case for mounting purposes. An easier
mounting method may be to use a cable tie wrap or zip
tie.
Positioning the electronics module so that it is not the
low point in the cable will keep liquids from running
down the cable and into the electronics. Take care to
route the sensor cable to avoid crushing or crimping it
during use. Damage to the sensor cable may affect the
desired set points and overall operation of the
electronics.
Theory of Operation
The KD-2440 system operates on a traditional Colpitts
oscillator circuit where the sensor acts as the resonating
coil for the oscillator. The proximity of the target to the
sensor face pulls
the oscillator, changing its frequency
and amplitude of modulation, controlling a variable gain
oscillator section within the electronic circuit.
5CM Sensor Response Data:
5CM Sensor Response Data:
0
2
4
6
8
10
12
14
0 50 100 150
303 SS Output for 12 & 24V Inputs
Displacement, Mils
DC Output Voltage
24 Vdc High Gain
12 Vdc High Gain
24 Vdc Low Gain
12 Vdc Low Gain
0
2
4
6
8
10
12
14
0 50 100 150
Aluminum
303 Stainless
4130 Steel
Outputs at Medium Gain & 24 Volt Input
Displacement, Mils
DC Output Voltage
0
2
4
6
8
10
12
14
16
18
0 50 100 150
4130 Steel Output for 12 & 24 Volt Inputs
Displacement, Mils
DC Output Voltage
24 Vdc High Gain
12 Vdc High Gain
24 Vdc Low Gain
12 Vdc Low Gain
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
100 1000 10000
Bandwidth, Hz
Differential Noise, m
V
p-p
4130 Steel
Aluminum
304 Stainless
Example Output Noise @ 12Vdc Input, Mid
Gain, Medium Displacement
0
2
4
6
8
10
12
0 50 100 150
Aluminum
303 Stainless
4130 Steel
Outputs at Medium Gain & 12 Volt Input
Displacement, Mils
DC Output Voltage
1
3
5
7
9
11
13
0 50 100 150
24Vdc Low Gain
12Vdc Low Gain
12Vdc High Gain
24Vdc High Gain
Aluminum Output for 12 & 24 Volt Inputs
DC Output Voltage
Displacement, Mils
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