Clean the exterior of the enclosure as needed to remove excess buildup of dust, debris, or other contamination.
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Ensure the enclosure door is shut while cleaning to prevent contact with internal components.
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Use a non-conductive, non-residue cleaner (for example, 70% isopropyl alcohol / 30% water mixture) and a soft cloth that will not scratch the enclosure surface.
Vibration sensors used in industrial condition monitoring do not require routine periodic recalibration, but calibration should be verified when:
-
A sensor is replaced
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Anomalous readings are suspected
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A mechanical event (impact, flooding, or fire) occurs that may have damaged the sensor
Verification is performed by comparing the sensor output on a calibrated shaker table. It can also be helpful to compare the sensor against a known reference using a calibrated back-to-back reference accelerometer, or by confirming DC gap voltage for proximity probes is within the expected linear range at the installed gap. For IEPE accelerometers, the presence of a DC bias voltage on the signal line while the sensor is powered confirms the sensor is receiving constant-current excitation; a loss of bias voltage indicates a wiring or power supply fault.
Note
The NI C Series input modules (NI-9229, NI-9230, NI-9232, etc.) are factory-calibrated and do not require field calibration under normal operation.
For accelerometers and velocity probes:
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Confirm the sensor cable is fully seated at both the sensor connector and the terminal block inside the cRIO enclosure.
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For IEPE sensors (most industrial accelerometers), verify the constant-current supply is active by measuring DC bias voltage on the signal line. A healthy IEPE circuit shows approximately 8 to 12 VDC bias; zero volts indicates a broken wire, failed connector, or unpowered IEPE supply. InsightCM offers an open/short IEPE circuit indicator.
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Inspect the cable for physical damage along its run, particularly at the sensor connection (subject to vibration fatigue) and at conduit entry points.
For proximity probes:
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Verify the gap voltage is within the linear range of the driver (typically -8 to -18 V for a standard 200 mV/mil system).
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Confirm the proximitor/driver module is powered and its OK LED is illuminated.
The most common causes and corrective actions are:
|
Cause |
Corrective Action |
|---|---|
|
Grounding issues |
Verify the sensor cable shield is grounded at one end only to eliminate ground loops. |
|
Cable routing near power conductors |
Separate sensor signal cabling from power wiring per the Installation Planning Guide. |
|
Loose connectors |
Reseat and inspect all connectors at the sensor and terminal block for corrosion or partial seating. |
|
Improper sensor mounting |
Verify mounting torque or adhesive bond. A sensor not rigidly mounted picks up rocking or resonance artifacts rather than true machine vibration. |
|
Proximity probe contamination |
For proximity probes, erratic DC gap voltage indicates probe tip or target surface contamination or damage. |
Loss of communication with the cRIO device is most often caused by poor Ethernet termination or by port blocking or firewall rules. Troubleshoot in the following order:
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Verify the physical link using an Ethernet cable tester to confirm the cable run from the cRIO to its endpoint is intact.
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Confirm the network configuration of the cRIO, IP address and subnet, matches the network it is connecting to.
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If cabling and network settings are both confirmed correct, contact the facility’s IT group to verify that no firewall or port blocking is preventing the cRIO from communicating with the InsightCM server.