The Bently Nevada 330400-01-05, also cataloged as the 330400 Accelerometer, operates as a dedicated hardware component for sensing casing acceleration within rotating machinery monitoring systems.

Configuration Matrix

• Model: 330400

• Mounting: 1/4-28 UNF integral stud

• Sensitivity: 10.2 mV / m / s^2 (100 mV / g)

• Peak Acceleration Range: 490 m / s^2 (50 g)

Hardware Specifications

Rotor Dynamics and Acceleration Monitoring

This accelerometer is designed for casing-based vibration measurements, providing high-frequency response data necessary for detecting gear mesh frequencies, blade pass phenomena, and bearing housing defects. Unlike shaft-observing eddy-current probes that require gap voltage validation, the accelerometer converts inertial force directly into an electrical signal. The transducer maintains a transverse sensitivity of less than 5 percent and an amplitude of resonant peak restricted to 20 dB maximum to ensure signal fidelity. Proper installation is required to avoid mounting resonances that could mask valid machinery vibration data.

Ordering Information

• 330400-01-05 Accelerometer transducer unit

• Integral mounting stud (1/4-28 UNF)

• Note: Output cables and signal conditioning monitors (e.g., 3500/42M) are ordered separately

Field Installation Guidelines

• Surface Mounting: Ensure the mounting surface is flat, clean, and free of paint or debris. Surface roughness should not exceed 3.2 micrometers (125 micro-inches) Ra.

• Torque Application: Apply 3.4 N m (30 in-lbf) of torque to the mounting stud to ensure rigid mechanical coupling between the sensor and the machine casing.

• Signal Cable: Utilize a low-noise coaxial cable. Secure the cable near the sensor to prevent cable whip or strain from creating electrical noise in the high-frequency range.

• Grounding: The case-isolated design minimizes ground loop susceptibility; ensure the sensor housing does not contact multiple potential points.

Logistics and Handling

• Delivery time: 2-7 days when payment finish.

• Logistics: Shipped via DHL, FEDEX, or UPS.

• Packaging: All units are protected in anti-static industrial packaging to prevent electrostatic damage and physical transit hazards.

Frequently Asked Questions

• Q: How does the 330400 differ from the 330425?

  A: The 330400 has a sensitivity of 100 mV / g (50 g range), while the 330425 provides 25 mV / g (75 g range).

• Q: Can this sensor be used for radial shaft vibration?

  A: No, this is a case-mounted accelerometer for housing vibration; it does not measure relative shaft-to-bearing motion.

• Q: What is the purpose of the -8.5 VDC bias voltage?

  A: It serves as the DC offset for the output signal, allowing the vibration waveform to swing positive and negative within the sensor's linear range.

• Q: Is the stud replaceable?

  A: No, the 1/4-28 UNF mounting stud is integral to the sensor housing.

• Q: What is the maximum shock limit?

  A: The sensor is rated for a survival shock of 49,050 m / s^2 (5000 g) peak.

• Q: Does the sensor require a specific monitor?

  A: It is compatible with standard vibration monitoring systems that provide a constant current source of -24 VDC.

• Q: Can the sensor be mounted at any angle?

  A: Yes, but the sensitivity axis must be aligned with the vibration vector of interest.

• Q: How is the resonant frequency controlled?

  A: The design limits the resonant peak to 20 dB maximum to ensure a flat frequency response within the measurement band.