Equipment Health Monitoring- Proximity Sensor

1. PROXIMITY
TRANSDUCER
SYSTEM OPERATION

2. Copyright
Bently Nevada Corporation
All Rights Reserved, 1996
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The following marks are Bently Nevada Corporation’s Registered Trade Names:
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MicroPROX ADRE REBAM
Keyphasor Proximitor Seismoprobe
Key Velomitor TorXimitor
Trendmaster Smart Monitor Data Manager
Dynamic Data Manager Transient Data Manager Bently Nevada
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3. OUTER
SCREEN
CENTER
CONDUCTOR
INNER
SCREEN
INSULATION
TRIAXIAL CABLE

4. PROBE NUMBERING
CABLE
FIXED
LOCK NUT
TIP
ASSEMBLY
P/N 330106-05-30-10-02-00
S/N APRS 416567

5. EXTENSION CABLE NUMBERING
HEAT SHRINK SLEEVING
CONNECTOR
P/N 330130-080-00-00

6. PROXIMITOR
SIGNAL OUTPUT
SIGNAL COMMON
TRANSDUCER POWER
ELECTRICAL LENGTH

7. PROXIMITOR OPERATION
<100mil
RF SIGNAL
EXTENSION
CABLE
AND PROBE
PROXIMITOR
DEMODULATOR
OSCILLATOR
BENTLY
NEVADA

8. CONDUCTIVE
MATERIAL
EDDY CURRENTS
RF SIGNAL
BENTLY
NEVADA
EDDY CURRENT FLOW
R

9. RF SIGNAL
SMALL GAP
0

10. LARGE GAP
RF SIGNAL 0

11. RF SIGNAL
CHANGING GAP
0

12. DEMODULATOR OPERATION
DEMODULATOR
INPUT
PROXIMITOR
OUTPUT
0
0

13. RADIAL MOVEMENT
AXIAL MOVEMENT
RADIALAND AXIAL MOVEMENT

14. NOTCH
GAP
CHANGE
ONE
REVOLUTION
TIME
VOLTAGE
CHANGE
PROBE
OVER
SURFACE
PROBE
OVER
NOTCH
KEYPHASOR WITH NOTCH TARGET

15. VOLTAGE
CHANGE
PROJECTION
TIME
ONE
REVOLUTION
PROBE
OVER
PROJECTION
PROBE
OVER
SURFACE
KEYPHASOR WITH PROJECTION TARGET
GAP
CHANGE
BENTLY
NEVADA

16. CHANGE
IN
VOLTAGE
CHANGE IN GAP
24
OUTPUT
IN
VOLTS
-
DC
PROBE GAP
mils 0
0
10 20 30 40 50 60 70 80 90 100 110 120 130 140
2
4
6
8
10
12
14
16
18
20
22
PROXIMITOR CALIBRATION GRAPH

17. Average Scale
Factor (ASF)
equals:
change in gap voltage
change in gap

18. (-18.0Vdc) - (-2.0Vdc)
0.08in or 2.0 mm
= 200 mV/mil
or
= 7.87 mV/um

19. -24V SUPPLY
POWER SUPPLY VOLTAGE EFFECTS
PROBE GAP
-16V SUPPLY
OUTPUT
IN
VOLTS
-
DC
24
22
20
18
16
14
12
10
8
6
4
2
0
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140
mils

20. COMPONENT MISMATCH EFFECTS
PROBE GAP
OUTPUT
IN
VOLTS
-
DC
SHORT
CORRECT
LONG
24
22
20
18
16
14
12
10
8
6
4
2
0
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140
mils

21. TARGET MATERIAL EFFECTS
OUTPUT
IN
VOLTS
-
DC
PROBE GAP
4140 STEEL
TUNGSTEN
ALUMINUM
COPPER
24
22
20
18
16
14
12
10
8
6
4
2
0
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140
mils

22. CROSSTALK

23. SIDEVIEW

24. TARGET SIZE
YES
NO

25. PROXIMITOR CALIBRATION
EQUIPMENT SET-UP

26. PROXIMITOR CALIBRATION
EQUIPMENT SET-UP
DC VOLTMETER
-VT
INPUT
PROXIMITOR
EXTENSION CABLE
SPINDLE MICROMETER
TARGET
PROBE
BENTLY
NEVADA
out
com
vt

27. Q1. The three parts of a proximity transducer system are:
a.
b.
c.
Q2. The ruggedised coaxial cable used in the system has a center conductor
.
Q3. What is the electrical length of the following probe? 330106-05-30-05-02-0
.
Q4. What is the electrical length of the following extension cable?
330130-045-00-00 .
Q5. What is the total electrical length required by the following Proximitor?
330100-50-00 .
Probe
Extension cable
Proximitor
two screens
0.5M
4.5M
5.0M
APPLICATION EXERCISE

28. Q6. The Proximitor must be supplied with a dc voltage between
____________
and .
Q7. An field is created around the probe. It extends away from the
face of
the probe for linear range of at least .
Q8. When a conductive material is within range of the probe _____________
flow in the surface of that material.
Q9. A Proximitor must be calibrated to suit the it has as a target.
Q10. The dc output from the Proximitor will go more as the target
moves closer to the probe.
Q11. A proximity system frequency response is from to
and
-17.5 Vdc
-26.0 Vdc
RF
80 mils
eddy currents
material
positive
0Hz(dc) 10KHz
ac dc
APPLICATION EXERCISE

29. Q12. Name three applications for a proximity transducer system.
a.
b.
c. _____________________
Q13. Calculate the scale factor (sf) from the following: 90mils = 18.5Vdc,
10mils = 2.25Vdc. Is it within tolerance?
Q14. Name three reasons why a proximity system could be out of tolerance.
a.
b.
c.
Thrust measurement
Vibration measurement
Keyphasor
203mV/mil Yes, 1.5% error
Incorrect supply voltage
Mismatched components
Incorrect target material
APPLICATION EXERCISE