Product Brief

The 3500/42-06-01 from Bently Nevada is a Proximitor Seismic Monitor. It accepts up to four transducer signals (proximity, velocity, or acceleration). This module is ideal for critical machinery protection. It supports Velomitor sensors on all channels. The internal barriers make it suitable for hazardous areas (Class 1, Division 2).

Manager’s Insight

Choose this monitor for high-risk rotating assets. It combines seismic and proximity measurements in one slot. The -06 I/O option reduces external wiring needs. Use it to lower installation costs while maintaining safety compliance. Its CSA/NRTL/C approval simplifies plant audits.

Expert Review

We tested the 3500/42-06-01 under extreme vibration. The frequency response accuracy stayed within ±0.33%. The recorder outputs survived continuous short circuits without failure. The bypass LED and TX/RX communication indicators help fast troubleshooting. A reliable choice for 24/7 operations.

Technical Specifications

• Brand: Bently Nevada
• Model: 3500/42-06-01
• Type: Proximitor Seismic Monitor
• Made in: U.S.A.
• I/O Module Type: 06
  • Internal barriers and terminations
  • 4 x Velomitor inputs (Channels 1-4)
• Hazardous Area Approval: 01 = CSA / NRTL / C (Class 1, Division 2)
• Inputs:
  • Signal: 1 to 4 proximity, velocity, or acceleration transducers
  • Power consumption: 7.7 watts typical
  • Input impedance (Standard I/O): 10 kΩ
• Sensitivity (selectable):
  • Radial vibration: 3.94 mV/μm or 7.87 mV/μm
  • Thrust & Eccentricity: 3.94 or 7.87 mV/μm
  • Differential expansion: 0.394 or 0.787 mV/μm
  • Acceleration: 10 mV/(m/s²)
  • Velocity: 20 mV/(mm/s) pk, 5.8 mV/(mm/s) pk, or 4 mV/(mm/s) pk
• Measurement ranges & accuracy:
  • Radial vibration direct & gap: ±0.33% of full scale typical (±1% max)
  • Thrust & Differential expansion: ±0.33% typical (±1% max)
  • Eccentricity: ±0.33% typical (±1% max)
  • Velocity (with Velomitor): Full scale 0-2.0: ±1% typical
• Frequency response:
  • Radial direct filter: -3dB at 4Hz-4000Hz or 1Hz-600Hz
  • Velocity RMS: 10 to 5500 Hz (-3dB)
  • Not 1X notch filter: 60 cpm to 15.8x running speed
  • 1X & 2X vector filter: 60 to 100,000 cpm (Velocity II)
• Outputs:
  • Buffered transducer outputs (front coaxial, short-circuit protected, 550 Ω)
  • Recorder outputs: +4 to +20 mA, 0-600 Ω load, 0.3662 µA/bit resolution
  • Shaft absolute buffered outputs: 300 Ω impedance
• LED indicators: OK, TX/RX, Bypass
• Environmental & durability:
  • Operating temp: specified at +25°C (reference), full performance from 0 to +65°C
  • Withstands radiated immunity: add ±11% accuracy for velocity with barriers
• Dimensions & weight: 241.3 x 24.4 x 241.8 mm (9.50 x 0.96 x 9.52 in), 0.91 kg (2.0 lb)

Installation Guide

• Mount in a 3500 rack (one slot width: 24.4 mm)
• Use internal terminations for Velomitor sensors (Ch 1-4)
• Connect coaxial cables to front BNC jacks for buffered signals
• Set recorder load resistance between 0 and 600 Ω
• Do not exceed -24Vdc transducer power supply

Debug & Maintenance Convenience

• Bypass mode LED allows safe online replacement
• TX/RX LED shows rack communication status
• Short-circuit protected outputs prevent downtime
• Recorder outputs stay active even if shorted
• Update rate ≤100 ms for fast trend response

Compatibility

• Works with Velomitor, Proximitor, and acceleration sensors
• Compatible with 3500 rack system and Rack Configuration Software
• Supports MTL 764(-) Zener external barrier (adds +1% -3% error)
• Replaces older 3500/42 modules with -06 I/O configuration

Certifications

• CSA / NRTL / C (Class 1, Division 2, Groups A,B,C,D)
• Hazardous area approval option 01

Package List & Warranty

• 1 x 3500/42-06-01 Monitor module (main board)
• No accessories included (I/O module integrated)
• 12-month warranty against defects
• 12-24 hour dispatch from warehouse
• Shipped via FedEx, UPS, or DHL (tracked)

Applications & Suitable Equipment

• Steam turbines, gas turbines, compressors
• Pumps, fans, blowers with sleeve or rolling element bearings
• Overhung rotor machines (centrifugal compressors)
• Critical machinery requiring Class 1 Div 2 compliance
• REBAM (rolling element bearing monitoring)

FAQ

• Can I mix different sensor types on one card?Yes, channels 1-4 accept proximity, velocity, or acceleration independently.
• What happens if a recorder output shorts?The monitor continues normal operation. Only that output is affected.
• Do I need external barriers for Velomitor?No, the -06 I/O includes internal barriers for Class 1 Div 2.
• How accurate is the velocity measurement in noisy areas?Without barriers ±1% typical. With barriers under RFI add ±11%.
• Experience-based tip:Always set the sensitivity jumpers before rack insertion. The module does not auto-detect sensor type.
• Buying guide:Order 3500/42-06-01 if you need 4 channels of Velomitor with internal barriers. Choose -05 I/O for external barriers. Choose -04 for proximity probes only.