Proximity Probe Sensor Provides Optimum Performance and Outstanding Flexibility

Proximity sensors are playing an increasingly significant role in today’s machine monitoring applications, particularly in harsh industrial environments where systems require effective and reliable measurement of shaft vibration, position and speed on rotating plant.

Accurate monitoring of rotating machinery is an important part of condition monitoring and machine protection. Proximity probe systems can provide critical information about the condition and movement of rotating shafts, helping plant operators and maintenance teams monitor equipment performance and identify potential issues.

To meet these demands, condition monitoring specialists SENSONICS offer an established range of proximity probes, including a configurable universal driver option, the Senturion X eddy current proximity probe system (XPR04 Series). With the XED04 driver it is suitable for all standard probe cable length combinations.

The Senturion X provides a flexible approach to proximity measurement while maintaining the performance characteristics required for industrial machine monitoring applications. Its configurable design can also help simplify installation and spare parts management where different cable lengths are required across a plant.

Eddy current proximity probe technology

This innovative sensor incorporates a calibrated probe, extension cable and driver and performs non-contact distance measurement targeting a rotating machine shaft utilising the eddy current principle.

This combination forms a tuned circuit while the target material and variations in probe face to target distance are detected in this circuit by the driver.

The use of non-contact measurement makes eddy current proximity probes particularly suited to monitoring rotating machinery. By measuring the distance between the probe and the machine shaft, the system can provide information required for monitoring shaft position and vibration without physical contact with the rotating component.

This type of measurement system provides a linearised voltage output proportional to target gap with a API670 standard nominal sensitivity of 7.87mV/um for 2.5mm measurement range (or extended range version 3.94mV/µm for 4mm measurement range).

The system therefore provides a measurement solution for applications where accurate monitoring of shaft movement and position is required. Its compatibility with API 670 requirements also makes it suitable for integration with machine protection systems designed around this widely used standard.

Flexible proximity probe system lengths

The driver unit offers DIP switch selectable system lengths of 5m, 7m or 9m, with a front panel green LED indicating the selected option.

This provides flexibility on-site when installing the system, where it can be the case that different system lengths are required for various machine locations, with the additional benefit of minimising the spares holding.

The configurable approach means that the same driver platform can accommodate different standard cable lengths rather than requiring separate equipment configurations for every installation.

For industrial sites with multiple rotating machines and varying installation requirements, reducing the number of different components and spares required can simplify maintenance and equipment management.

Simplified commissioning and gap measurement

The gap voltage monitoring socket assists with commissioning the probe system; a voltmeter can be connected directly to the driver through the 3.5mm standard audio socket to display the gap voltage at the point of installation, while the probe mechanical gap can then be adjusted to suite the application.

This provides engineers with a straightforward method of checking the probe output during installation and commissioning. Being able to connect a voltmeter directly to the driver allows the gap voltage to be monitored at the point of installation before the proximity probe is put into normal operation.

The ability to adjust the mechanical gap to suit the application provides further flexibility when commissioning the system on different types of rotating machinery.

Robust cabling for harsh industrial environments

The cable system incorporates snap lock connectors which require no torquing and provide a shake proof solution important for heavy industrial applications.

The double screened cable offers robustness in combination with high immunity to interference and optional stainless steel convoluted armour is available for applications or environments where cable protection is paramount.

These features are designed to address some of the practical challenges associated with installing proximity sensors in demanding industrial environments. Heavy machinery can expose monitoring equipment and cabling to vibration, mechanical stresses and electrical interference, making robust connections and effective shielding important considerations.

The optional stainless steel convoluted armour provides an additional level of mechanical protection where the installation environment requires greater protection for the cable system.

API 670 compliant proximity probes and hazardous area applications

These proximity probes are designed to excel in demanding environments, full compliance to the API 670 standard ensures compatibility with third-party API670 compliant machine protection systems.

API 670 compatibility can be particularly important for industrial operators looking to integrate proximity measurement into existing machine monitoring and protection infrastructure. The ability to work with third-party API 670 compliant systems provides additional flexibility when specifying or upgrading machine protection arrangements.

Reliability of the system is underlined by Functional Safety certification to IEC 61508 SIL 2 as a single probe system.

For applications within hazardous areas where there is potential for explosive gases or dusts, Ex i intrinsically safe versions are available with ATEX/UKEX/IECEx/PESO certification.

The availability of intrinsically safe versions extends the application potential of the proximity probe system into hazardous environments where explosive atmospheres may be present. ATEX and UKEX certification are particularly relevant to installations in the UK and European markets where equipment may need to meet specific requirements for use in potentially explosive atmospheres.

The combination of machine monitoring capability, functional safety certification and hazardous area options provides flexibility for a broad range of industrial applications.

Universal driver reduces spares requirements

The universal driver concept follows on from other universal hardware platforms developed by Sensonics, such as the Sentry G3 monitoring and protection system which offers a single hardware platform for all the necessary turbine and pump vibration and supervisory measurements.

Reducing spares holding and field upgradability is a key advantage of adopting this latest generation of equipment.

The universal hardware approach provides a common platform that can help simplify the management of monitoring equipment across industrial sites. For maintenance teams, reducing the number of different components that need to be held as spares can help simplify stock management while potentially making equipment upgrades easier to implement.

For applications involving turbines, pumps and other rotating machinery, the ability to combine vibration and supervisory measurements within a flexible monitoring platform can also support a more consistent approach to condition monitoring and machine protection.

The Senturion X eddy current proximity probe system adds to Sensonics’ range of machine monitoring solutions by providing flexible, non-contact measurement of rotating shaft position and movement.

With selectable cable lengths, straightforward commissioning, robust cable connections, optional armouring and availability for hazardous area applications, the XPR04 Series is designed to provide a practical proximity measurement solution for demanding industrial environments.

Sensonics Proximity Probes