Bently Nevada 330400-02-05 Accelerometer Acceleration Tranducer

Product Overview

The Bently Nevada 330400-02-05 is a three-wire piezoelectric accelerometer with an M8 x 1 integral stud and multiple hazardous area approvals (CSA, ATEX, IECEx). Designed for critical machinery casing acceleration measurement, it meets API Standard 670 and delivers 100 mV/g sensitivity with a 50 g peak amplitude range. The metric M8 x 1 mounting thread is ideal for European and Asian OEM machinery, eliminating the need for Imperial-to-metric adapter bushings that can loosen under vibration.

Key Specifications

• Product Type: Piezoelectric Accelerometer / Acceleration Transducer
• Mounting Thread: M8 x 1 integral stud
• Agency Approvals: 05 = Multiple (CSA, ATEX, IECEx)
• Sensitivity: 10.2 mV/m/s² (100 mV/g) ±5%
• Acceleration Range: 490 m/s² (50 g) peak overall
• Amplitude Linearity: ±1% to 490 m/s² (50 g) peak
• Frequency Response: 10 Hz to 15 kHz (±3 dB); 30 Hz to 10 kHz (±10%)
• Broadband Noise Floor: 0.039 m/s² (0.004 g) rms (10 Hz to 15 kHz)
• Mounted Resonant Frequency: >30 kHz
• Transverse Sensitivity: <5% of axial
• Temperature Sensitivity: -11% to +3% typical
• Operating Temperature: -55°C to +121°C (-67°F to +250°F)
• Storage Temperature: -55°C to +121°C (-67°F to +250°F)
• Relative Humidity: 100% condensing (hermetically sealed case)
• IP Rating: Equivalent to IP68 (sensor body only)
• Power Requirements: -24 ±0.5 Vdc; 2 mA nominal bias current
• Output Bias Voltage: -8.5 ±0.5 Vdc
• Grounding: Case isolated
• Case Material: 316L stainless steel
• Dimensions: 23 mm (0.93 in) diameter x 59 mm (2.3 in) height
• Weight: 100 g (3.5 oz) typical (without cable)
• Mounting Torque: 4.1 N·m (3.0 ft·lb)
• Shock Survivability: 49,050 m/s² (5,000 g) peak

Features & Benefits

• Metric M8 x 1 integral stud — direct mounting on European and Asian machinery without adapter bushings, eliminating a common failure mode where Imperial-to-metric adapters loosen under cyclic vibration
• API 670 compliant — meets global oil & gas and petrochemical specifications for accelerometer performance and reliability
• Multiple hazardous area certifications — CSA, ATEX, and IECEx approvals enable single-SKU global deployment across North America, Europe, and international projects
• Case-isolated, hermetically sealed design — 316L stainless steel housing with isolated ground prevents electrical noise and withstands corrosive, 100% condensing environments
• Wide 10 Hz to 15 kHz frequency response — captures gear mesh, bearing defect, and blade pass frequencies for comprehensive machine diagnostics
• Ultra-low noise floor — 0.004 g rms enables detection of early-stage bearing pitting and gear tooth cracks before they propagate to failure

Typical Applications

• Gear mesh monitoring on European-manufactured gearboxes and speed increasers
• Bearing housing acceleration on Siemens, ABB, and other metric-standard turbomachinery
• Wind turbine gearbox and generator bearing health monitoring (metric mount)
• Machine tool spindle vibration monitoring on CNC equipment with M8 mounting
• Reciprocating compressor crosshead and frame acceleration measurement
• Offshore platform and refinery hazardous area installations requiring ATEX/IECEx certification

Installation Guide

1. Verify hazardous area requirements — confirm zone classification and ensure the -05 suffix covers your region (CSA for North America, ATEX for Europe, IECEx for international).
2. Prepare M8 x 1 mounting hole — machine a flat surface (32 μin rms) and drill/tap an M8 x 1 hole perpendicular to the vibration measurement axis. Depth must accommodate the full stud length plus one thread.
3. Clean mounting surface — remove oil, paint, and debris with isopropyl alcohol. A clean, flat surface is critical for high-frequency response above 5 kHz.
4. Apply mounting torque — tighten to 4.1 N·m (3.0 ft·lb) using a calibrated torque wrench. Do not exceed this value — the piezoelectric crystal will fracture under excessive preload.
5. Connect cable — use Bently Nevada 130539-XX, 16925-XX, or 16710-XX series cable with the 3-pin MIL-C-5015 connector. Thread the connector fully and verify the seal.
6. Apply -24 Vdc power — connect to a regulated supply. Verify -8.5 Vdc bias and 100 mV/g sensitivity using a reference shaker or known vibration source.
7. Route and secure cable — avoid sharp bends (<25 mm radius), maintain 300 mm from VFD cables, and secure with cable ties every 300 mm to prevent fatigue.

FAQ

Q: What is the difference between 330400-02-05 and 330400-01-05?
A: The 330400-02-05 has an M8 x 1 integral stud (metric), while the 330400-01-05 has a ¼-28 UNF integral stud (Imperial). Both have identical electrical performance and -05 hazardous area approvals. Choose based on your machine's threaded hole standard.

Q: What is the difference between 330400-02-05 and 330400-02-00?
A: The 330400-02-05 includes multiple agency approvals (CSA, ATEX, IECEx), while the 330400-02-00 has no approvals. Both have M8 x 1 mounting. Choose -05 for hazardous areas; choose -00 for general industrial applications.

Q: Do I need a mounting base for M8 x 1 installation?
A: For serial numbers preceded by "G" (post-April 2004), the mounting base is optional. For older sensors, use mounting base 37439-02 (M8 x 1 to M8 x 1) to reduce base strain sensitivity from 0.100 g/μstrain to 0.0005 g/μstrain.

Q: Can I use this for integration to velocity?
A: Not recommended. Integration amplifies low-frequency noise and can mask true machine condition. For velocity monitoring, Bently Nevada recommends the 330500 Velomitor Sensor which is specifically designed for velocity output.

Q: What is the maximum cable length?
A: 305 meters (1,000 feet) with no signal degradation. Bently Nevada offers standard cables from 6 ft to 99 ft in 1-foot increments. For custom lengths, consult factory.

Selection Tips

• Select 330400-02-05 when your machinery has M8 x 1 threaded holes and you require hazardous area approvals for global deployment.
• If your equipment uses ¼-28 UNF threads, choose 330400-01-05 to avoid metric-to-Imperial adapter issues.
• For non-hazardous industrial environments, the 330400-02-00 provides identical performance at lower cost.
• If your application requires higher g-range (75 g peak) or lower sensitivity (25 mV/g), consider the 330425-02-05 instead.
• Always verify serial number prefix — if your sensor does not start with "G", budget for mounting base 37439-02 to achieve API 670 base strain requirements.
• Confirm your monitor input impedance is ≥10 kΩ to prevent signal loading and attenuation.