Bentley 330101-02-12-05-02-00 Eddy Current Probe Detailed Description

I. Product Introduction

330101-02-12-05-02-00 is a standard non-armored eddy current probe of the 3300 XL 8mm series from Bently Nevada under Baker Hughes. It is the core front-end sensing component of the rotating machinery TSI condition monitoring system and must be combined with the same series extension cable and preamplifier to form a complete measurement chain. The product adopts an ultra-short housing + extremely short non-threaded section + 0.5-meter short cable design, specifically tailored for shallow holes, extremely narrow spaces, and short-distance signal transmission conditions. Based on the eddy current effect, it achieves non-contact high-precision measurement and is mainly used for radial shaft vibration, axial displacement, phase angle, and rotational speed monitoring. It complies with API 670 industry standards and has the characteristics of compact structure, convenient installation, strong anti-interference ability, and high stability. It is widely used in large-scale unit condition monitoring in conventional industrial areas such as power, petrochemical, and metallurgy.

II. Basic Information

Model: 330101-02-12-05-02-00

Brand: Bently Nevada

Series: 3300 XL 8mm Eddy Current Sensor System

Type: Standard non-armored proximity eddy current probe (330101 is non-armored version, different from 330102 armored version)

Thread Specification: 3/8-24 UNF American fine thread, highly versatile

Model Code Meaning: 02 = Length of non-threaded section 0.2 inches; 12 = Total housing length 1.2 inches (ultra-short housing); 05 = Length of probe's built-in cable 0.5 meters; 02 = Micro ClickLoc coaxial connector, standard non-armored cable; 00 = No explosion-proof certification, conventional industrial configuration

Structural Features: The housing is made of AISI 303/304 stainless steel, the sensing end is made of high-temperature resistant PPS material; non-armored flexible short cable, length 0.5 meters; patented TipLoc one-piece molding process, the end is firmly bonded to the housing, resistant to vibration loosening, ultra-short rod suitable for shallow hole installation

Connector Type: Micro ClickLoc coaxial connector, tool-free insertion and removal, reliable connection

Certification: CE, UL industrial safety and electromagnetic compatibility certification, no explosion-proof qualification, only applicable to non-flammable and non-explosive working conditions

Protection Grade: IP54 (probe body), suitable for dry, low dust, and non-corrosive environments

Compatible Systems: 3300 XL full series preamplifiers, 3300/3500 series TSI monitoring cards, compatible with mainstream PLC, DCS

III. Electrical Parameters

Sensitivity: 7.87V/mm (200mV/mil), full-scale linear error ≤ ±1%, full temperature range stability ≤ ±1.5%

Linear Range: 2.0mm (80mil), effective working range 0.25mm–2.3mm

Output Signal: Cooperates with preamplifier to output -1VDC to -17VDC standard DC voltage

Frequency Response: 0–10kHz (+0/-3dB), covers the full vibration frequency band of rotating machinery

Probe DC Resistance: 7.59Ω ± 0.50Ω (0.5-meter cable)

Minimum Target Diameter: 8.9mm (0.35 inches), recommended shaft diameter ≥ 50.8mm (2 inches)

System Compatibility: Requires matching with 3300 XL preamplifiers, the total electrical length (probe cable + extension cable) must be consistent with the calibration length of the preamplifier, and it is strictly prohibited to randomly cut the cable

IV. Environmental and Mechanical Parameters

Environmental Parameters Working temperature: -52℃ to + 177℃, can withstand + 218℃ for a short period of time

Storage temperature: -52℃ to + 260℃

Relative humidity: 5%–95% (no condensation), no strong corrosive gases

Anti-interference: Complies with CE EMI/RFI standards, can withstand strong electromagnetic interference from frequency converters and motors

Explosion-proof rating: No explosion-proof certification, only applicable to non-hazardous areas

Mechanical parameters

Length of non-threaded section: 0.2 inches (extremely short optical rod, suitable for shallow holes)

Total length of the housing: 1.2 inches (ultra-short housing, preferred for space-constrained measurement points)

Cable specification: 0.5-meter standard non-armored flexible cable, resistant to oil and aging, suitable for short-distance installation

Installation torque: Recommended 1.1–1.4N・m, avoid damage to the threads or deformation of the housing

Cable bending radius: ≥ 3 times the cable diameter, prohibit sharp-angle bending, dragging

Weight: Approximately 0.08kg, lightweight design, convenient for installation

Five. Core functions

1. Non-contact precise measurement

Based on the eddy current effect, the end coil of the probe receives the 0.5–2MHz high-frequency excitation signal from the preamplifier, generating an alternating magnetic field; when close to the metal shaft, the surface of the shaft induces eddy currents, reversing the impedance of the coil, combined with the preamplifier to convert it into a linear voltage signal, accurately reflecting the change in the gap between the probe and the shaft, simultaneously collecting static displacement and dynamic vibration signals, with nanometer-level accuracy, without mechanical wear.

2. Ultra-short structure suitable for extreme narrow spaces

0.2-inch extremely short optical rod + 1.2-inch ultra-short housing, specially designed for shallow holes, equipment side walls, compact brackets, etc., where conventional probes cannot be installed; the stainless steel housing has strong rigidity, resistance to vibration, deformation, and no loosening over the long term, with high installation coaxiality.

3. 0.5-meter short cable suitable for short-distance transmission

0.5-meter non-armored flexible short cable, suitable for close connection scenarios between the probe and the preamplifier / extension cable, reducing cable redundancy and interference, simple wiring; the flexible material is convenient for bending and laying in narrow spaces, maintaining the original length to ensure impedance matching, cannot be cut.

4. Wide temperature stability and temperature compensation

Built-in high-temperature coil and insulation materials, combined with the system's automatic temperature compensation circuit, in the - 52℃ to + 177℃ wide temperature range, the sensitivity fluctuation is ≤ ±1.5%, suppressing temperature drift, ensuring stable long-term monitoring data.

5. Fault self-check and rapid maintenance

Can be coordinated with the matching preamplifier to achieve line fault detection, accurately identifying probe breakage, short circuit, cable damage, poor contact of the connector, etc., outputting dedicated fault voltage signals, triggering alarms; probes, extension cables, and preamplifiers of the same specification can be interchanged, on-site replacement does not require recalibration, shortening downtime.

Six. Working principle

The sensing coil inside the probe is supplied with high-frequency alternating current to form a stable electromagnetic field, the electromagnetic field penetrates the air gap and acts on the measured metal shaft, inducing a closed eddy current on the metal surface; the intensity of the eddy current changes with the gap between the probe and the shaft, inversely affecting the electrical parameters such as the inductance and impedance of the probe coil; the probe transmits the changing signal to the preamplifier, the preamplifier converts it into a continuous DC voltage at a ratio of 7.87V/mm, the voltage is closer to - 17VDC when the gap is larger, closer to - 1VDC when the gap is smaller; the upper-level system interprets the voltage values, converts them into parameters such as shaft vibration, axial displacement, speed, phase, etc., achieving online monitoring and safety protection of the equipment state.

Seven. Installation and laying specifications

Installation position: Vertically installed on the radial or axial direction of the measured shaft, the probe end face is parallel to the shaft surface, avoiding measurement errors caused by inclination; when installing in shallow holes, ensure the hole is clean, without interference from foreign objects. Gap setting: It is recommended to set at the midpoint of the linear range (approximately 1.27mm), corresponding to a -9VDC output from the preamplifier, to achieve the best linearity and stability.

Thread installation: Insert the 3/8-24 UNF thread into the dedicated base, with the torque controlled at 1.1–1.4N・m. Do not forcefully tighten to avoid damaging the thread.

Cable laying: The 0.5-meter short cable should have a bending radius of ≥3 times the cable diameter. Avoid sharp-angle bending; separate the cable from the power cable for routing, and protect it with a conduit to prevent mechanical damage and keep away from high-temperature heat sources.

Connection of connectors: Insert the micro ClickLoc connector into the slot, and it will lock when you hear a "click" sound. Take precautions for dust protection of the connector and regularly check its tightness.

VIII. Typical application scenarios

Power industry: Auxiliary equipment such as steam turbine generators, boiler feed pumps, and induced draft fans of power plants, with shallow-hole measurement points for monitoring shaft vibration and axial displacement, to warn of bearing wear and rotor friction.

Petrochemical industry: Centrifugal compressors, process pumps, and mixing units in conventional non-explosion-proof areas, for monitoring vibration and displacement to ensure long-term stable operation of the equipment.

Metallurgical industry: High-temperature blast furnace fans, large transmission motors, and rolling mill rotating mechanisms, for monitoring vibration and displacement to avoid equipment overload damage risks.

General machinery: Key phase acquisition, speed measurement, and eccentricity analysis of various large rotating machinery, providing data for dynamic balance correction and fault diagnosis.

TSI system complement: As the front-end component of the 3300 XL system, paired with the preamplifier and monitoring card, to build a safety monitoring system for rotating machinery in conventional industrial areas.

IX. Product advantages

Ultra-compact: 0.2-inch short optical rod + 1.2-inch ultra-short housing, suitable for shallow holes and narrow spaces, with flexible installation.

Short-distance compatibility: 0.5-meter short cable, suitable for short-range signal transmission, with simple wiring and reduced interference.

High precision and stability: 7.87V/mm standard sensitivity, with small linear error, strong wide-temperature stability, meeting API 670 standards.

Convenient maintenance: Micro ClickLoc connector can be plugged and unplugged without tools, with strong component interchangeability, and no need for calibration during on-site replacement.

Industrial durability: Stainless steel housing + heat-resistant end, anti-vibration, anti-aging, supporting 7×24-hour continuous operation.