Bently Nevada | 330400-01-00 | 1/4-28 Accelerometer

Product Overview

The Bently Nevada 330400-01-00 is a piezoelectric accelerometer engineered for critical machinery casing acceleration measurements. It features a 1/4-28 UNF integral stud mounting and provides a sensitivity of 10.2 mV/m/s² (100 mV/g) with a peak measurement range of 490 m/s² (50 g). Designed to meet API Standard 670, this sensor is suited for gear mesh monitoring, bearing vibration analysis, and comprehensive machinery health assessment.

Key Specifications

• Sensor Type: Piezoelectric accelerometer
• Mounting Thread: 1/4-28 UNF integral stud
• Sensitivity: 10.2 mV/m/s² (100 mV/g) ±5%
• Acceleration Range: 490 m/s² (50 g) peak
• Frequency Response: 10 Hz to 15 kHz (600 cpm to 900,000 cpm) ±3 dB
• Amplitude Linearity: ±1% to 490 m/s² (50 g) peak
• Broadband Noise Floor: 0.039 m/s² (0.004 g) rms (10 Hz to 15 kHz)
• Transverse Sensitivity: Less than 5% of axial sensitivity
• Mounted Resonant Frequency: Greater than 30 kHz
• Dimensions: 23 mm diameter x 59 mm height (including stud)
• Weight: 99 g (3.5 oz), excluding cable
• Connector: 3-pin MIL-C-5015 receptacle
• Operating Temperature: -55°C to +121°C (-67°F to +250°F)
• Mounting Torque: 4.1 N·m (3.0 ft·lb)

Features and Benefits

• 100 mV/g sensitivity provides excellent signal resolution for low-amplitude vibration detection
• Broad 10 Hz to 15 kHz frequency response captures gear mesh, bearing defect, and casing vibration data
• 1/4-28 UNF integral stud is the industry-standard thread for North American rotating equipment
• Compact 23 mm diameter housing fits in tight spaces on motors, pumps, and gearboxes
• Exceptional amplitude linearity of ±1% ensures accurate measurement across the full 50 g range
• API 670 compliance qualifies the sensor for use in petrochemical and power generation protection systems

Applications

• Gear mesh frequency monitoring on industrial gearboxes
• Anti-friction bearing casing vibration measurement
• General rotating machinery health monitoring programs
• Centrifugal pump and motor vibration assessment
• Steam turbine and gas turbine casing acceleration measurement

FAQ

Q: How do I interpret the Bently Nevada 330400 accelerometer ordering code?
A: The model uses a four-digit suffix. The first two digits define the mounting thread: -01 = 1/4-28 UNF integral stud, -02 = M8 x 1 integral stud. The last two digits define certifications: -00 = no approvals, -05 = multiple agency approvals (CSA, ATEX, IECEx). Thus, 330400-01-00 means 1/4-28 UNF stud with no agency approvals.

Q: What is the difference between 330400-01-00 and 330400-02-00?
A: 330400-01-00 has a 1/4-28 UNF integral stud; 330400-02-00 has an M8 x 1 integral stud. Electrical specifications are identical.

Q: Are agency approvals included with the -00 suffix?
A: No. The -00 option indicates no agency approvals. For certified versions, select 330400-01-05.

Q: What is the recommended mounting torque?
A: Tighten the sensor to 4.1 N·m (3.0 ft·lb) for optimal vibration transmission and secure retention.

Q: Can this accelerometer measure in any orientation?
A: Yes. The 330400 is designed for operation in any mounting orientation without performance degradation.

Installation Guide

1. Ensure the machine mounting surface is clean, flat, and free of debris or coatings
2. Machine the mounting surface to 32 microinch rms or better finish
3. Apply a thin layer of silicone grease or coupling fluid to the mounting interface
4. Thread the 1/4-28 UNF stud into the prepared tapped hole
5. Torque to 4.1 N·m (3.0 ft·lb) using a properly calibrated torque wrench
6. Attach the 3-pin MIL-C-5015 cable to the sensor connector
7. Secure the cable with strain relief clamps away from heat and moving parts
8. Verify signal integrity at the vibration monitor before commissioning

Selection Tips

• Select 330400-01-00 for 1/4-28 UNF stud mounting without agency approvals
• For M8 x 1 stud mounting, choose 330400-02-00
• For 1/4-28 mounting with CSA/ATEX/IECEx approvals, select 330400-01-05
• For M8 mounting with approvals, select 330400-02-05
• For applications requiring 75 g peak range, evaluate the 330425 series
• Confirm the data acquisition system accepts 100 mV/g piezoelectric inputs
• Source MIL-C-5015 terminated cable compatible with your monitor input