Configured for absolute vibration measurement in machinery condition monitoring systems, the Bently Nevada 330500-03-04 (330500 Velomitor Piezo-Velocity Sensor) provides direct electrical conversion of housing vibration into a proportional velocity output. The sensor integrates a piezoelectric sensing element with internal signal conditioning and is intended for continuous monitoring of bearing housings, machine casings, and structural vibration points.
Suffix Breakdown & Model Matrix
The supplied documentation identifies 330500-03-04 as a complete ordering model. No official suffix definition or ordering matrix is provided; therefore, no suffix interpretation is included.
Hardware Specifications
Parameter
Specification
Model
330500-03-04
Brand
Bently Nevada
Product Type
Velomitor Piezo-Velocity Sensor
Origin
USA
Shipping Location
Xiamen, China
Weight
0.1 kg
Dimensions
7.8 x 2.5 x 2.5 cm
Case Material
316L stainless steel
Operating Temp
-55 deg C to +121 deg C
Relative Humidity
Up to 100%, non-submerged, hermetically sealed
Shock Survivability
5000 g peak maximum
Output Signal
3.94 mV/mm/s (100 mV/in/s)
Sensitivity
100 mV/in/s +/-5%
Velocity Range
Up to 1270 mm/s (50 in/s) peak
Frequency Response
4.5 Hz to 5 kHz (270 to 300000 cpm)
Power Consumption
Internal electronics; external power consumption not specified
Rotor Dynamics Measurement Characteristics
The sensor measures absolute casing vibration by generating a velocity-proportional output directly from its internal piezoelectric sensing element. Within machinery protection systems, this signal can be evaluated together with displacement and phase measurements to support rotor dynamics analysis, including identification of imbalance, shaft misalignment, mechanical looseness, and rolling-element bearing defects. Signal generation is performed internally without the moving-coil mechanism associated with conventional velocity transducers.
Frequently Asked Questions
Q: Does this sensor require periodic gap voltage adjustment similar to an eddy-current proximity probe? A: No. The 330500-03-04 is a piezo-velocity sensor and does not require proximity probe gap voltage adjustment. Gap voltage verification applies to eddy-current displacement probe systems rather than velocity sensors.
Q: Is the housing suitable for moisture and oil exposure? A: Yes. The sensor uses a hermetically sealed 316L stainless steel housing designed for industrial environments with exposure to moisture, oil, dust, and temperature variation. It is specified for up to 100% relative humidity under non-submerged conditions.
Q: Can the sensor be installed while machinery is operating? A: Installation should follow the plant maintenance procedure. Mounting surfaces must be clean and mechanically secure before the sensor is tightened to the specified installation torque to maintain consistent vibration transmission.
Field Installation Guidelines
Verify that the mounting surface is flat, clean, and free from paint, corrosion, or debris before installation.
Apply one drop of medium-strength threadlocker, such as Loctite 242 or an equivalent product, to both ends of the adapter stud.
Apply a thin layer of ultrasonic couplant or light machine oil between the mounting pad and sensor contact surface to improve mechanical coupling.
Hand-tighten the 1/4-28 UNF mounting stud into the sensor body before final tightening.
Tighten the sensor using a calibrated torque wrench to 2.7 to 4.5 N m (24 to 40 in lbf).
Route the sensor cable separately from high-power conductors where practical and follow the site's shielding and grounding practices to reduce electrical interference.
Inspect the mounting interface periodically to confirm that the threaded connection remains secure and free of mechanical damage.
