Product Overview

The Bently Nevada 330500-07-00 is a rugged, 1/4-28 UNF threaded Velomitor designed for absolute vibration monitoring on machine casings and bearing housings. Unlike proximity probes that observe the shaft relative to the bearing, the Velomitor utilizes a piezoelectric ceramic element to sense the movement of the machine itself. By integrating the acceleration signal into a velocity output internally, it provides a direct measurement of vibration severity. Its solid-state, no-moving-parts construction makes it exceptionally durable and suitable for harsh industrial environments where mechanical "moving-coil" velocity sensors would typically fail.

Definitive Technical Specifications

Industrial Applications and Deployment

The 330500-07-00 is a critical component for monitoring general-purpose machinery where shaft access is unavailable or unnecessary. It is the primary choice for detecting casing-related issues such as structural resonance, piping vibration, and anti-friction (rolling element) bearing defects. In power generation and oil & gas facilities, these sensors are mounted on motor housings, pump frames, and gearboxes. Because the output is velocity-based, it aligns with most ISO vibration standards for machine health assessment. Its omnidirectional mounting capability allows it to be installed in cramped or inverted positions without affecting the signal accuracy or frequency response.

FAQ

Q: Why are the dimensions in this listing different from common proximity probes?

A: Proximity probes are long, thin sensors designed to reach through machine walls. The 330500 Velomitor is a "casing sensor," meaning it sits on the outside of the machine. It is a compact cylinder roughly 2.5 inches tall and 1 inch wide.

Q: Can this sensor be used for high-frequency gear mesh analysis?

A: Yes, with a frequency response up to 5 kHz, the Velomitor is capable of capturing the fundamental frequencies of gear mesh and high-speed rolling element bearing faults, though specialized accelerometers are sometimes preferred for much higher ultrasonic ranges.

Q: Does the -07-00 model include a mounting adapter?

A: The -07 suffix specifically designates the 1/4-28 UNF mounting thread. In this configuration, the base of the sensor is threaded directly. If you require a different thread (like M8 or 3/8-16), a different option suffix would be needed.

Q: Is a special power supply required for the 330500?

A: It is typically powered by a -24 Vdc supply provided by a Bently Nevada monitor (such as the 3500/42M) or a compatible signal conditioner. It operates on a two-wire system where the signal is superimposed on the power line.

Q: Is the 330500 sensor waterproof?

A: The case is hermetically sealed and made of 316L stainless steel, designed for 100% humidity environments. However, for submerged applications, special waterproof cables and connectors must be used to protect the pin interface.