Emerson A6140 Shaft Absolute Vibration Monitor
A two-channel AMS 6500 monitor that combines shaft-relative displacement and case vibration to calculate absolute shaft vibration.
Product Identification
A6140 is an Emerson AMS 6500 dual-channel shaft absolute vibration monitor. It phase-compensates and mathematically combines a non-contact displacement signal with a case-mounted seismic or piezoelectric vibration signal.
The result represents shaft movement relative to free space, supporting protection on sleeve-bearing machines where both rotor and bearing-case movement are significant.
Engineering Data
| Manufacturer | Emerson |
|---|---|
| Model | A6140 |
| System | AMS 6500 Machinery Health Monitor |
| Measurement | Shaft absolute vibration |
| Channels | Two; independent or combined |
| Module Format | 3U, one slot, hot swappable |
| Compliance Basis | API 670 |
| Channel 1 Sensors | 6422, 6423, 6424 or 6425 displacement sensor with compatible CON driver |
| Channel 2 Sensor | 6125 case vibration sensor or compatible seismic/piezoelectric input |
| Channel 1 Input | -1 to -23 VDC; lower cutoff 1 or 5 Hz; upper cutoff 50–2000 Hz adjustable |
| Channel 2 Input | -5 to +15 VDC; lower cutoff 5 or 10 Hz; upper cutoff 50–1000 or 1600 Hz adjustable |
| Outputs | 0/4–20 mA and 0–10 V proportional outputs plus buffered signals |
| Power | Maximum 6 W; 250 mA at 24 VDC |
Functions
- Combines relative shaft displacement and case motion into an absolute shaft-vibration value.
- Provides independent and combined channel modes with configurable ranges and filtering.
- Includes front indicators, buffered outputs, proportional outputs and self-checking diagnostics.
- Supports alert and danger setpoints, delays, hysteresis and relay integration.
Applications
- Configuration-controlled industrial maintenance and shutdown planning
- Exact-suffix spare identification for installed automation assets
- Reliability support where labels, revisions and interfaces must remain traceable
Lifecycle
- Record the complete model, host equipment, hardware revision and removal photographs in the asset history.
- Store the spare in clean, dry, ESD-safe packaging with connectors and mechanical interfaces protected.
- Confirm current manufacturer lifecycle status and an approved migration path before a critical outage.
FAQ
A6140: What evidence is needed to reproduce the combined measurement?
Provide both sensor chains, sensitivities, channel phase convention, filter settings, ranges and the approved configuration file.
A6140: Can only one sensor be changed without reviewing the combined channel?
A component may be replaced, but the complete relative-plus-case chain must be revalidated for sensitivity, polarity, phase and scaling.
A6140: Which machines benefit most from shaft-absolute monitoring?
It is useful when rotor and bearing-case masses are closely matched and case movement is significant during operation.
A6140: What should a module exchange test cover?
Simulate both channels, verify independent and combined values, proportional outputs, alarms, relays, diagnostics and communication.
A6140: How can a phase or polarity error be detected?
Compare relative, case and combined channels during controlled operation and verify that the mathematical result follows the approved vector convention.
A6140: What should be recorded for a critical spare?
Keep rack and slot identity, hardware revision, configuration checksum, sensor list, last test results and preservation history.
