330750 and 330752 High Temperature
Velomitor System
Datasheet

Bently Nevada Machinery Condition Monitoring141639 Rev. T

Description
The 330750 and 330752 High Temperature Velomitor Systemsensor head and integral cable are designed for hightemperature environments. This enables you to mount thesensing head on surfaces with temperatures up to +400°C(+752°F).
Earlier versions of the 330750 and 330752 High
Temperature Velomitor System were limited toenvironments with a maximum temperature of+300°C (+572°F). The serial number of current
versions that measure up to +400°C (+752°F) arepreceded by the letter "G".
To accomplish this, the transducer design segregates thesensing element from the signal conditioning electronics. The
two are permanently connected using an integrated cable.
The integrated cable eliminates connectors which are asignificant source of transducer failures.
The cable enables you to position the signal conditioning
electronics in a cooler location. The internal electronics
withstands temperatures of 55°C to +121°C (-67°F to +250°F).
The integrated design makes it possible to capturemachinery performance data comparable to other Bently
Nevada Velomitor transducers, but at significantly highertemperatures.
For lower temperature environments, use the standard
330500 Velomitor Piezo-velocity Sensor. You can install it inlocations with a maximum operating temperature of +121°C(+250°F).

330750 and 330752 High Temperature Velomitor System
Datasheet141639 Rev. T

Most common machine
malfunctions (unbalance,misalignment, etc.) occur on therotor and originate as an increase (orat least a change) in rotor vibration.
For any individual casing
measurement to be effective foroverall machine protection, thesystem must continually transmit asignificant amount of rotor vibration
to the machine casing, or mounting
location of the transducer.
In addition, be careful to install theaccelerometer transducer on the bearing
housing or machine casing. Improper
installation may decrease the transducer
amplitude and frequency response and/orgenerate false signals that do not represent
actual vibration. Refer to the appropriate
instruction manuals and Application Notes.
Upon request, Bently Nevada provides
engineering services that can identify theappropriate machine housing measurements
and installation assistance if needed.

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330750 and 330752 High Temperature Velomitor System
Datasheet141639 Rev. T

Specifications
Parameters are specified from +20 to +30°C(+68 to +86°F) and 100 Hz unless otherwise
indicated.

Frequency
Response

15 to 2000 Hz (900 to 120,000cpm) ± 3.0 dB;
20 to 1000 Hz (1,200 to 60,000cpm) ± 0.9 dB

Transient
Temperature
Sensitivity

0.0762 mm/s/°C (0.003
in/s/°C), typical, as defined in
ISO 5347-18:1993(E)Amplitude
Range

635 mm/s (25 in/s) peak
below 680 Hz.
2940 m/s2 (300 g) peakabove 680 Hz.
Vibration at frequencies
above 2 kHz decreases thisrange.

TransverseSensitivity

Less than 5% of Sensitivity

Amplitude
Linearity±2% to 152 mm/s (6 in/s)
peakMounted
Resonant
Frequency

Greater than 5 kHz

Output Bias
Voltage-12 ±2.0 VDCBroadband
Noise Floor(15Hz to 2kHz)

0.127 mm/s (0.005 in/s) rms
nominalMaximum
Cable Length

305 meters (1000 feet) withno degradation of signal.

Operating and Storage Temperature Range

Electrical
Sensitivity

Case Isolated

Environmental Limits

Operating the Velomitor transducer
outside the specified limits may resultin false readings, failure of thetransducer or loss of machinemonitoring.

5.7 mV/mm/s (145 mV/in/s)±5%

GroundingSensing Head

Maximum mounted surface
temperature -55°C to+400°C (-67°F to +752°F)

IntegralHardline Cable-55° to +400°C(-67° to +752°F)

Electronics-55° to +121°C(-67° to +250°F)

Shock
Survivability

24,535 m/s2 (2500 g) peak

Relative
Humidity

To 100% non-submerged;
case is hermetically sealed.

Physical
Weight (typical)
2 meters

635 grams (1.40 lb)

4 meters

794 grams (1.75 lb)

6 meters953 grams (2.10 lb)

8 meters

1,111 grams (2.45 lb)

Mounting

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See 330750 System
Dimensional Drawing on
page 10.
See 330752 System
Dimensional Drawing on
page 11.

Case

300 series stainless steel

Connector

2-pin Mil-C-5015 receptacle,
hermetically-sealed, 304
stainless steel shell.

330750 and 330752 High Temperature Velomitor System
Datasheet

Polarity

When the applied velocity isfrom the base to the top of
the transducer, Pin A
becomes positive withrespect to Pin B.

Bend Radius

Minimum bend radius of
51mm (2.0in)

141639 Rev. TCompliance andCertifications
FCC
This device complies with part 15 of theFCC Rules. Operation is subject to thefollowing two conditions:

Before installing this product, werecommend you read the 330750
and 330752 High Temperature
Velomitor System User Guide(document 135090)

llThis device may not cause harmfulinterference.
This device must accept any
interference received, includinginterference that may cause
undesired operation.

EMC
EMC Directive 2014/30/EU

RoHS
RoHS Directive 2011/65/EU

Maritime
330400 and 330425 onlyABS 2009 Steel Vessels Rules
1-1-4/7.7,4-8-3/1.11.1,4-9-7/134/15

330750 and 330752 High Temperature Velomitor System
Datasheet141639 Rev. T

Hazardous Area Approvals
Entity Parameters for Zone 0/1 and Zone 2

For the detailed listing of country andproduct specific approvals, refer tothe Approvals Quick Reference Guide(108M1756) available from Bently.com.

CSA/NRTL/C
Ex ia IICClass I, Zone 0, AEx ia IIC
Class I, Division 1, Groups A, B, C and D
Class II, Division 1, Groups E, F and G
Class III, Division 1
Ex nL IIC
Ex ec IICClass I, Division 2, Groups A, B, C and DGroupIICIIC

Type330750330750
Type S330752
330752Type S

Ui

28 V

28 V

Ii

120 mA

120 mA

Pi

1.0 W

1.0 W

Ci

1 ηF

1 ηF

Li30 μH

30 μH

Hazardous Area Conditions of Safe
Use

ATEX/IECEx

ATEX/IECEx

II 1 G

Zone 0/1:
Equipment must be connected to equipmentthat meets the above listed entity parameters.

Ex ia IIC or IIB Ta, T4 492°C
II 3 GEx na IIC or IIB Ta, T4, T1 492°C Gc

The cables type A or B (in compliance with EN
60079-25) must respect the cable parameterslisted with the entity parameters.

Ex ec IIC or IIB Ta T4, T1 492°C Gc

Special Notes

Ta, T1, T4 492°C
Ta, T4, T1 492°ClTemperature
ClassTemperature Range

T4-40°C to +100°C

T1-40°C to +400°Clll

This equipment is intrinsically safe andcan be used in potentially explosive
atmospheres.
This system is intrinsically safe whenconnected to an associated intrinsicallysafe power supply meeting the entity
parameters.
Operating ambient temperature -40°C to+100°C (Electronic Housing)Operating ambient temperature -40°C to+400°C (Sensor and Cable)

Zone 2 :The supply electrical parameters shall not
exceed the values mentioned in the tablesabove.

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330750 and 330752 High Temperature Velomitor SystemDatasheet

141639 Rev. TSpecial Noteslllllll

The equipment is safe when connected
to an associated source, containing a
reliable material limiting current andvoltage meeting the entity parameters.
Operating ambient temperature -40°C to+100°C (Electronic Housing)Operating ambient temperature -40°C to+400°C (Sensor and Cable)
The mating part of the connector shallprovide IP54 ingress protection or better
according to requirements of IEC 60079-0
and IEC 60079-7 or IEC 60079-15.
Provisions shall be made for ensuringthat the rated voltage and current are
not exceeded while in service.
Shall be supplied from Class II limited
energy source according torequirements of C22.2 No 61010-1-12 andUL 61010-1 3rd Edition.
Transient protection shall be provided
that is set at a level not exceeding 140 % ofthe peak rated voltage value at thesupply terminals to the equipment.

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330750 and 330752 High Temperature Velomitor SystemDatasheet

141639 Rev. T

Interconnection Cables

Ordering Information

The standard cable lengths below are available.
You can order custom cable lengths inincrements of one foot at additional cost. Somecables have a minimum and maximum length.
For details, see each part description below.

For the detailed listing of country andproduct specific approvals, refer tothe Approvals Quick Reference Guide(108M1756) available from Bently.com.

Standard Cable Lengths

330750-AA-BB

Feet

Meters (approximate)

A: Length

6 ft

1.8 m

20

2 meters

8 ft

2.4 m

40

4 meters

10 ft

3.0 m

60

6 meters

12 ft

3.6 m

80

8 meters

15 ft4.5 m

17 ft

5.0 m

20 ft

6.0 m

25 ft

7.6 m

330752-AA-BB

30 ft

9.0 m

A: Length

33 ft

10.0 m25

2.5 meters

50 ft

15.2 m40

4 meters

99 ft

30.0 m60

6 meters

80

8 meters

B: Approvals
05

Multiple Approvals (CSA, ATEX, andIECEx)

B: Approvals
05

Multiple Approvals (CSA, ATEX, andIECEx)

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330750 and 330752 High Temperature Velomitor System
Datasheet141639 Rev. T

Cable Part Numbers
Part number

Part number

at the HTVS end and ringlugs at the monitor end.
Temperature range -29 to
121°C (-20 to 250°F). See
Short Run Interconnect
Cable on page 14.

Description

When entering a part number, use‘NN’ in the part numbers to specify
the length (in feet) of the cable youwant to order.

9571-NN

Standard interconnect
cableCE installation interconnect
cable (**required for CEinstallations)Shielded 0.382 mm2 (22AWG) cable with a moistureresistant female connector
at the HTVS end and ringlugs at the monitor end.
Temperature range -29 to121°C (-20 to 250°F). See
Standard Interconnect
Cable on page 13.

Shielded 0.382 mm2 (22AWG) cable with a splashproof boot over a female
connector at the HTVS end
and flush cut at the monitor
end. Temperature range -55
to 125°C (-67°F to 257°F). See
CE Installation Interconnect
Cable on page 14.

02173034

0.963 mm2 (18 AWG) bulkcableStandard armoredinterconnect cable

84661-NN

02173006

Stainless steel armor overshielded 0.382 mm2 (22AWG) cable with a moistureresistant female connector
at the HTVS end and ringlugs at the monitor end.
Temperature range -29 to121°C (-20 to 250°F). See
Standard ArmoredInterconnect Cable onpage 13.

02173007

Standard ArmoredInterconnect Cable. See
Standard Right-angle
Interconnect Cable on
page 13.

Shielded twisted pair. Same
cable as used on 9571-NN
and 84661-NN. Specify thenumber of feet. The
maximum length thatshould be used with theHTVS is 305 m (1000 ft)
Spare connector

00502025

Same connector as used on9571-NN and 84661-NN
Right angle connector

Short run interconnect
cable122129-NN

Shielded twisted pair. Same
cable as used on 89477-NN
and 122129-NN. Specify thenumber of feet.
0.382 mm2 (22 AWG) bulk
cable

Right angle interconnectcable89477-NN

Description

101212-01

Shielded 0.963 mm2 (18AWG) cable with a moistureresistant female connector

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Right angle connector kit.
Same connector as used on
89477-NN.

330750 and 330752 High Temperature Velomitor System
DatasheetPart number

00531061

330535141639 Rev. T

Part number

Description

Description

Spare mating connector

Seal Ring

Mating connector for 330750
and 330752 Velomitor
System.

One-inch sealing lock ringused to mount theelectronics housing. Tworings are required to mountthe electronics.

Standard temperature
cable03818072

22 AWG, double-shieldedcable
Cable Mounting Clamp

00530574

Mating connector clamp tobe used with 00531061

Cable Clamp

Electronics Housing Strap

03818073

One-inch rigid conduit strap
for securing the electronics
housing.

169546

Electronics Mounting Hub
One-inch weather tight hub
used to mount theelectronics housing in aweatherproof enclosure.
03818071

9/15

Stainless steel mesh tie
down clamp for the hardline
cable. For temperatures
greater than 260C (500F).

330750 and 330752 High Temperature Velomitor System
Datasheet141639 Rev. TGraphs and Figures(All dimensions are in millimeters (inches))
Figure 1: 330750 System Dimensional Drawing

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330750 and 330752 High Temperature Velomitor System
Datasheet141639 Rev. T(All dimensions are in millimeters (inches))
Figure 2: 330752 System Dimensional Drawing

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330750 and 330752 High Temperature Velomitor System
Datasheet141639 Rev. T

Figure 3: Velocity Amplitude

Figure 4: Velocity Phase Error

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Datasheet141639 Rev. T

The Velomitor requires a two-conductor cable. We recommend using a double-shieldedcable to minimize noise interference.

Figure 5: Standard Interconnect Cable

Figure 6: Standard Armored Interconnect Cable

Figure 7: Standard Right-angle Interconnect Cable

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330750 and 330752 High Temperature Velomitor System
Datasheet141639 Rev. T

Figure 8: Short Run Interconnect Cable

Figure 9: CE Installation Interconnect Cable

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330750 and 330752 High Temperature Velomitor System
Datasheet141639 Rev. T

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Bently Nevada, Velomitor and Orbit Logo are registered trademarks of Bently Nevada, a Baker Hughes Business, in theUnited States and other countries. The Baker Hughes logo is a trademark of Baker Hughes Company. All otherproduct and company names are trademarks of their respective holders. Use of the trademarks does not imply any
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notice or obligation. Contact your Baker Hughes representative for the most current information.
The information contained in this document is the property of Baker Hughes and its affiliates; and is subject tochange without prior notice. It is being supplied as a service to our customers and may not be altered or its content
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1631 Bently Parkway South, Minden, Nevada USA 89423
Phone: 1.775.782.3611 (US) or Bently.com/support
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