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YOKOGAWA AXFA11G-D1-21
Product Introduction:
The AXFA11G-D1-21 is a full-spectrum vibration transmitter from Yokogawa’s AXFA product line, designed for continuous online vibration monitoring of rotating machinery. The “11G” indicates the standard vibration measurement range (0 to 11 mm/s velocity or equivalent), “D1” specifies the output configuration (4–20 mA + HART), and “21” denotes the mechanical mounting and process connection variant. This transmitter provides comprehensive spectral vibration data for predictive maintenance programs.
Detailed content
Technical Specifications:
- Measurement Type: Full-spectrum vibration (velocity, acceleration, displacement)
- Velocity Range: 0 to 11.2 mm/s RMS (unfiltered), 0 to 4.5 mm/s RMS (filtered)
- Frequency Range: 10 Hz to 1000 Hz (full spectrum)
- Output Signal: 4 to 20 mA DC (HART 7 protocol)
- Accuracy: ±1% of full scale (velocity), ±5% of full scale (acceleration)
- Temperature Range: -40°C to +85°C
- Protection Rating: IP67 (IEC 60529)
- Power Supply: 18 to 36 V DC (loop-powered)
- Housing Material: 316L Stainless Steel
Functional Features:
- Measures full vibration spectrum (10 Hz – 1000 Hz) — not just 1x RPM
- Detects bearing defects, imbalance, misalignment, looseness, and resonance through spectral analysis
- HART 7 communication for remote configuration, trending, and diagnostics
- Built-in sensor diagnostics — detects cable break, sensor degradation, and mounting looseness
- Two-stage alarm output (warning and danger) configurable via HART
Performance Parameters:
| Parameter | Value |
|---|---|
| Frequency Resolution | 1 Hz (FFT-based, 400 line resolution) |
| Dynamic Range | ≥60 dB |
| Sensitivity (Velocity) | 20 mV/mm/s ±5% |
| Sensor Type Compatibility | IEPE (ICP) accelerometer, velocity sensor (moving coil) |
| Maximum Shock Rating | 100 g peak, 11 ms half-sine |
| MTBF | ≥100,000 hours |
Material Composition:
- Housing: 316L Stainless Steel (electropolished finish, Ra ≤ 0.8 μm)
- Cable Gland: Nickel-plated brass with Viton O-ring seal
- Internal PCB: Conformal-coated, MIL-STD-810G compliant
Structural Characteristics:
- Dimensions: 70 mm (diameter) × 145 mm (length)
- Weight: Approximately 0.85 kg
- Mounting: Magnetic base (included) or stud mount (M8 × 1.25 thread)
- Connector: M12 × 1, 5-pin (power + signal + sensor)
Working Principle:
The AXFA11G-D1-21 receives vibration signals from an IEPE accelerometer or velocity sensor. The internal 24-bit sigma-delta A/D converter samples the signal at 25.6 kHz, then performs real-time FFT (Fast Fourier Transform) to decompose the signal into its frequency components. The RMS velocity is calculated across the full 10–1000 Hz band and output as a 4–20 mA signal. Simultaneously, HART FSK modulation carries diagnostic and spectral trend data to the host system.
Key Advantages:
- Full-spectrum measurement (not just 1x RPM) — detects early-stage bearing faults missed by traditional transmitters
- IP67 stainless steel housing — suitable for harsh industrial environments including offshore platforms
- HART 7 with advanced diagnostics — reduces unplanned downtime by up to 50%
- Magnetic base mounting — enables quick installation on ferrous machinery surfaces
Applicable Industries:
- Oil and gas (pumps, compressors, turbines)
- Power generation (steam turbines, generators, fans)
- Mining and minerals processing (SAG mills, crushers)
- Pulp and paper (refiners, fans, pumps)
- Cement and steel production
Installation Requirements:
- Mount on a flat, clean ferrous surface using the magnetic base (surface roughness Ra ≤ 6.3 μm)
- Ensure sensor cable length does not exceed 100 meters (for IEPE sensors)
- Connect 4–20 mA loop to a HART-compatible DCS/PLC or handheld communicator
- Orient the transmitter so the M12 connector faces downward to prevent water ingress
Usage Precautions:
- Do not exceed the maximum input acceleration of 50 g RMS — will saturate the A/D converter
- Calibrate the sensor sensitivity in the transmitter configuration before commissioning
- Do not install on surfaces with vibration amplitude exceeding 25 mm/s — mechanical damage risk
- Perform spectral baseline measurement during commissioning for future trend comparison
