3500/70M

Overview

3500/70M is a four-channel Recip Impulse Velocity Monitor designed for reciprocating compressors, monitoring crankcase and crosshead vibration. It processes seismic transducer inputs, derives vibration measurements, and triggers user-programmable alarms.

Recip Velocity Accuracy

• Typical: ±0.33% of full scale
• Maximum: ±1% (excluding filters)
• Velomitor Accuracy Degradation:
  • Full Scale 0-0.5: ±3% typical
  • Full Scale 0-1.0: ±2% typical
  • Full Scale 0-2.0: ±1% typical

Frequency Response

• Bias Filter: -3 dB at 0.01 Hz (1-pole, low-pass)
• Not OK Filter: -3 dB at 2400 Hz (1-pole, low-pass)
• Integration Filter: -3 dB at 0.34 Hz (1-pole, low-pass)
• RMS Static Values: -3 dB at 0.1 Hz (1-pole, low-pass)
• Peak Static Values: -3 dB at 0.3 Hz (1-pole, low-pass)
• 1X & 2X Vector Filter: Constant Q filter with bandwidth ±3% of running speed (Q = 16.7)

Filter Quality

• High-Pass: 4-pole, 80 dB per decade, 24 dB per octave
• Low-Pass: 2-pole, 40 dB per decade, 12 dB per octave

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