Velomitor® Piezo-Velocity Sensor

Bently Nevada™ Asset Condition Monitoring

Description
Velomitor® Piezo-velocity Sensors measure absolute (relative to free space)
bearing housing, casing, or structural vibration. Unlike moving-coil velocity
transducers, such as the Bently Nevada™ Seismoprobe® family of velocity
transducers, Velomitor Piezo-velocity Sensors incorporate a solid-state design,
and are specialized piezoelectric accelerometers with embedded integration
electronics. Because they incorporate solid-state electronics with no moving
parts, they do not suffer from mechanical degradation and wear, and can be
mounted vertically, horizontally, or at any other angle of orientation.

BENTLY
NEVADA
MADE IN U. S. A.
R
Application Advisory
VELOMITOR
PN 330500 If you plan to make housing measurements for overall machine
100 mV/in/s
(4 mV/mm/s)
protection, consider the usefulness of the measurement for each
application. Most common machine malfunctions (imbalance,
misalignment, etc.) originate at the rotor and cause an increase
(or at least a change) in rotor vibration. For any housing
measurement to be effective for overall machine protection, the
machine must faithfully transmit a significant amount of rotor
vibration to the bearing housing or machine casing, or more
specifically, to the mounting location of the transducer.
In addition, you should exercise care with the physical installation
of the transducer. Improper installation can degrade the
transducer’s performance, and/or generate signals that do not
represent actual machine vibration. Integration of the output to
displacement can make this worse. Exercise extreme caution if
integrating to displacement in any case.

Upon request, we can provide engineering services to determine the suitability of

housing measurements for the machine in question and/or to provide
installation assistance.

Specifications and Ordering Information

Part Number 141632-01
Rev. E (06/08)

Page 1 of 8
 Hazardous Area Approvals
Specifications Multiple approvals for hazardous areas certified by
Parameters are specified from +20 °C to +30 °C (+68 Canadian Standards Association (CSA/NRTL/C) in
°F to +86 °F) and at 100 Hz unless otherwise North America and by LCIE in Europe.
indicated. North America
Note: Operation outside the specified limits may result in false Class I, Div 1
readings or loss of machine monitoring. Groups A, B, C & D, Class II
Groups E, F, and G, Class III
Electrical When installed per drawing
Sensitivity 103778
3.94 mV/mm/s (100 mV/in/s) ±5%. T5

Frequency Class I Div 2 only when installed

Response per drawing 103779
4.5 Hz to 5 kHz (270 cpm to 300
kcpm) ±3.0 dB. European/
6.0 Hz to 2.5 kHz (360 cpm to 150 CENELEC
kcpm) ±0.9 dB. II 1 G
Temperature EEx ia IIC T4 certificate
Sensitivity number LCIE 04ATEX6042X
T4 @ Ta = (-40°C-100°C).
-14% to +7.5% typical over the
operating temperature range. II 3 G
Velocity Range EEx nL IIC T4 certificate
number LCIE 04ATEX6041X
1270 mm/s (50 in/s) peak. T4 @ Ta = (-40°C-100°C).
Transverse
Sensitivity IECEx

<5% of sensitivity. Ex nL IIC T4

T4 @ Ta = (-40°C-100°C).
Amplitude Serial Number IECEx LCI 06.0002
Linearity
±2% to 152 mm/s (6 in/s) peak.
Environmental Limits
Mounted
Operating
Resonant
Temperature
Frequency
Range
Greater than 12 kHz.
−55 °C to +121 °C (−67 °F to
Broadband +250 °F).
Noise Floor (4.5
Shock
Hz to 5 kHz)
Survivability
0.004 mm/s (160 µin/s) rms,
5000 g (49033 m/s2) peak,
nominal
maximum
Maximum Cable
Relative
Length
Humidity
305 metres (1,000 feet) of cable
To 100% non-submerged; case is
(part number 02173006) with no
hermetically-sealed.
degradation of signal.

Specifications and Ordering Information

Part Number 141632-01
Rev. E (06/08)

Page 2 of 8
Base Strain 84661-AXX
Sensitivity
Used with monitors. Not for use
0.005 in/s/µstrain. with 21128 Velocity Transducer
Housing.
Magnetic Field
Susceptibility Description
<51 µin/s/gauss (50 gauss, 50- 2-conductor twisted, shielded 22
60Hz). AWG armored cable.
Physical Terminations
Weight 2-socket moisture-resistant
142 g (5.0 oz), typical. female connector at one end,
terminal lugs at the other end.
Diameter
89477-AXX
25.3 mm (0.995 in).
Used with monitors and with
Height 21128 Velocity Transducer
63.2 mm (2.49 in). Housing.

Case Material Description

304L stainless steel. 2-conductor 18 AWG twisted,

shielded cable.
Connector
Terminations
2-pin Mil-C-5015 hermetically-
sealed, 304 stainless steel shell. Right-angle 2-socket plug at one
end, terminal lugs at the other
Mounting end.
Torque
125065-AXX
46 kg-cm (40 in-lbf) max.
Used with monitors. Not for use
Polarity with 21128 Velocity Transducer
Pin A goes positive with respect to Housing.
Pin B when the sensor case Description
motion is toward the connector.
2-conductor 18 AWG twisted,
Cables shielded cable.
Terminations
9571-AXX
2-socket plug and fluorosilicone
Used with monitors. Not for use elastomer boot at one end,
with 21128 Velocity Transducer terminal lugs at the other.
Description
Ordering Information
2-conductor twisted, shielded 22
AWG cable Velomitor Piezo-velocity Sensor
Terminations 330500-AXX-BXX
2-socket moisture-resistant A: Mounting Thread Adapter Option
female connector at one end, 00 No adapter
terminal lugs at the other end. 01 1/2 - 20 UNF
02 M8 x 1
03 1/4 - 28 UNF
04 1/4 - 20 UNC

Specifications and Ordering Information

Part Number 141632-01
Rev. E (06/08)

Page 3 of 8
 05 Unavailable for 330500. 1 2 = 12 ft
For 1/4-18 NPT mounting,
order 330525. Velocity Transducer Housing Assembly
06 5/8 – 18 UNF 21128-AXX-BXX
07 3/8 – 16 UNC
08 1/2 – 13 UNC A: Mounting Thread Option
B: Agency Approval Option 01 Unthreaded
00 Not required 02 3/4 - 14 NPT
01 CSA/NRTL/C 03 1/2 - 14 NPT
02 SIRA/CENELEC 04 1/2 - 12 BSP
04 Multiple approvals B: Cable Exit Fitting Option
01 1/2 - 14 NPT plug
2-Conductor Twisted-Pair 22 AWG Cable with Female 02 1/2 -14 NPT explosion-proof
Plug and Terminal Lugs 03 1/2 -14 NPT explosion-proof
9571-AXX with cable gland seal
Note: Applications that use the 21128 housing require cable
A: Cable length Option in feet part number 89477-AXX to connect the Velomitor sensor
to a monitor.
Order in increments of 1.0 ft (305 mm).
Minimum: 2.0 ft (0.6 m)
Velocity Transducer Housing – CENELEC approved
Maximum: 99 ft (30 m)
Example: 0 9 = 9 ft 107770-AXX-BXX
1 2 = 12 ft This part is a 21128 Housing with a 330500
Velomitor Sensor pre-installed at the factory. This
2-Conductor Twisted-Pair 22 AWG Armored Cable with part is rated for CENELEC Zone 1, Group IIC
Female Plug and Terminal Lugs hazardous area applications.
84661-AXX
A: Mounting Thread Option
A: Cable length Option in feet
01 Unthreaded
Order in increments of 1.0 ft (305 mm). 02 3/4 - 14 NPT
Minimum: 3.0 ft (0.9 m) 03 1/2 - 14 NPT
Maximum: 96 ft (29 m) 04 1/2 - 14 BSP
Example: 0 9 = 9 ft
B: Cable Exit Fitting Option
1 2 = 12 ft
01 1/2 - 14 NPT plug
02 1/2 - 14 NPT explosion-proof
2-Conductor Twisted-Pair 18 AWG Cable with Right Angle
03 1/2 - 14 NPT explosion-proof
Plug and Terminal Lugs
with cable gland seal
89477-AXX
Accessories
A: Cable length Option in feet
100076-01
Order in increments of 1.0 ft (305 mm).
Minimum: 2.0 ft (0.6 m) 330500 Velomitor Sensor and
Maximum: 99 ft (30 m) Velomitor XA Sensor Manual.
Example: 0 9 = 9 ft
1 2 = 12 ft 02173006
Bulk cable. 2-conductor 18 AWG
2-Conductor Twisted-Pair 18 AWG Cable with twisted, shielded cable without
Fluorosilicone-Booted Plug and Terminal Lugs connectors or terminal lugs.
125065-AXX Specify number of feet.
A: Cable length Option in feet 46000-01
Order in increments of 1.0 ft (305 mm). Magnetic base for temporary
Minimum: 2.0 ft (0.6 m) mounting of Velomitor Sensors.
Maximum: 99 ft (30 m) Used with 1/4-28 UNF mounting
Example: 0 9 = 9 ft thread adapters.
Specifications and Ordering Information
Part Number 141632-01
Rev. E (06/08)

Page 4 of 8
46122-01 89413-01
Quick Connect for semi- Individual 1/4-18 NPT mounting
permanent mounting of adapter. Spares only. For new
Velomitor Sensors. Used with installations, order 330525
1/2-20 UNF mounting thread velometer.
adapters.
04300015
89409-01
Individual 5/8-18 UNF mounting
Individual 1/2-20 UNF mounting adapter.
adapter.
161191
89410-01
Individual 1/2-13 UNC mounting
Individual M8 x 1 mounting adapter.
adapter. Note: The Velomitor Sensor is shipped
with an adapter. Individual
89411-01 adapters are available as spares.
Individual 1/4–28 UNF mounting 101212-01
adapter. Velomitor Sensor connector kit.
89412-01 Used with housings and retrofits.
Individual 1/4 - 20 UNC 123135-01
mounting adapter. Velomitor Sensor Power Module.

Specifications and Ordering Information

Part Number 141632-01
Rev. E (06/08)

Page 5 of 8
Graphs and Figures
Note: All dimension shown in millimetres (inches) except as noted.

63.2
(2.49) BENTLY
NEVADA
MADE IN U.S.A.
R
VELOMITOR
PN 330500
100 mV/in/s
(4 mV/mm/s)

4
3

1. 2-pin, MIL-C-5015 receptacle

2. 15/16-inch hexagonal
3. 12.7 (0.500) diameter, 0.8 (0.030) deep counterbore
4. 25.3 (0.995) diameter
5. 3/8-24 UNF-2B, 6.4 (0.250) minimum threaded depth, 14.0 (0.550) maximum drill depth

Figure 1: Velomitor Piezo-Velocity Sensor Dimensional Drawing

Specifications and Ordering Information

Part Number 141632-01
Rev. E (06/08)

Page 6 of 8
 2

1
dB referenced to 100 Hz

-1

-2
1 10 100 1000 10000
Frequency (Hz)

Figure 2: Typical Amplitude Response

100

80
Phase Lag Angle (degrees)

60

40

20

-20
1 10 100 1000 10000

Frequency (Hz)

Figure 3: Typical Phase Response

Specifications and Ordering Information

Part Number 141632-01
Rev. E (06/08)

Page 7 of 8
 Copyright 1999. Bently Nevada LLC.
1631 Bently Parkway South, Minden, Nevada USA 89423
Phone: 775.782.3611 Fax: 775.215.2873
www.ge-energy.com/bently
All rights reserved.

Bently Nevada, Velomitor, and Seismoprobe are trademarks of General Electric Company.

Specifications and Ordering Information

Part Number 141632-01
Rev. E (06/08)

Page 8 of 8