VEL/G Series Vibration Sensor
• Heavy Industrial
• Stainless Steel Hermetically Sealed Dual Case
• Self-Generating, 2 wire 4-20mA loop power, IEPE 2-wire options
• High Noise Immunity
• Choice of cable lengths with or without armouring
• Top or Side exit connector or conduit
• Operating Temperature range -40⁰C to +100⁰C
• High Temperature opt. +200⁰C
• Multi Hazardous Area Approved
Description
The VEL/G Series self-generating transducer produces a signal proportional to the velocity component of a mechanical vibration by means of relative movement between a coil and a magnet. The rugged construction and fully sealed body enables this transducer to be used in most Industrial environments.
The main body of the transducer is fitted with a polished stainless steel case and
contains a moving coil and magnet assembly. The coil is suspended within the field of
the magnet by means of diaphragms which permit virtually frictionless movement in one axis only. This measuring axis is coincident with the axis of the cylindrical body.
VEL/G Series are simple to interface with monitoring equipment or directly integrate to SCADA systems (PLC/DCS) in conjunction with low noise makes them particularly suitable for the applications where the grounding and electrical interference environment is a challenge.
Methods of mounting vary from integral, threaded studs of various sizes to integral
mounting plates (refer to order codes for details). The transducer is supplied with either
an electrical connector fitted to the top or side of the upper body, or an integral top or
side exit cable.
Series vibration sensor consists of a high-performance shear mode piezoelectric ceramic assembly available in either a top exit or side exit hermetically sealed housing. The PZ Series with an acceleration measurement range of over 50g is suitable for vibration monitoring applications on a wide range of critical rotating machinery and typically mounted on the bearing housing to detect bearing wear and absolute vibration.
The sensor operates on a current-loop principle which permits long interconnecting cables to be used without loss of measurement accuracy. The full Series includes transducers of accelerometer and velomitor, and transmitter of vibration velocity, with standard output of 100mV/g, 4mV/mm/s and 4-20mA respectively.
The piezoelectric shear mode sensing element and signal conditioner are contained within an inner metal enclosure, which is electrically and thermally insulated from the outer stainless-steel body. The arrangement prevents the opportunity for earth loops eliminating electrical interference, and in addition minimises thermal shocks and base strain effects. The inner enclosure is connected to the 0V of the two-wire system and is
therefore an effective electrical screen. External connections are available through a
wide range of integral cable and connector options.
• Heavy Industrial
• Stainless Steel Hermetically Sealed Dual Case
• Self-Generating, 2 wire 4-20mA loop power, IEPE 2-wire options
• High Noise Immunity
• Choice of cable lengths with or without armouring
• Top or Side exit connector or conduit
• Operating Temperature range -40⁰C to +100⁰C
• High Temperature opt. +200⁰C
• Multi Hazardous Area Approved
Caution
If housing measurements are being used for overall protection of the machine, thought should be given to the usefulness of the measurement for each application. Most common machine malfunctions (imbalance, misalignment, etc.) originate at the rotor and cause a change of rotor vibration. For any housing measurement alone to be effective for protection purpose, a significant amount of rotor vibration must be faithfully transmitted to the bearing housing or machine casing, or more specifically, to the mounting location of the transducer. In addition, care should be taken in the physical installation of the transducer. Improper installation can result in a degradation of the transducer’s performance, and signals generated not representing actual machine vibration. Integration of the output to displacement can worsen this. Extreme caution should be exercised if integrating to displacement.
Datasheets: VELG Series Vibration Sensor Iss1.0.pdf
