Non-contact proximity sensor

eddy currentcylindricalATEX

Product Overview
Proximity probes are non-contact eddy-current sensors designed to precisely measure shaft vibration and axial thrust position in rotating equipment. These monitoring solutions are essential for ensuring the safe, efficient operation of assets such as hydrogenerators, turbines, pumps, and fans. By continuously tracking mechanical behaviors like imbalance, misalignment, and axial displacement, proximity probes enable early detection of faults—supporting predictive maintenance strategies that reduce unplanned downtime, improve reliability, and extend equipment life.

• Three complementary proximity probe solutions: Smart Proximity System, Integrated Proximity Probe, Analog Proximity System
• Designed for advanced data integration, streamlined setup, or rugged compliance for harsh conditions

Smart Proximity System (SPS)
The Smart Proximity System is a modular, high-performance eddy-current solution designed for advanced condition monitoring and protection. With a built-in Modbus interface, it delivers time-based calculated values such as pk, pk-pk, and mean shaft position (gap). These values are computed directly at the transmitter level, minimizing the need for external processing and allowing seamless integration into modern SCADA, DCS, or edge monitoring platforms.

• Pre-processed vibration and position data available via Modbus
• Interchangeable components (probe, extension cable, and transmitter) simplify maintenance and spare parts management

SPS Key Features

• Measurement ranges: 2mm (8mV/μm) and 4mm (4mV/μm)
• Frequency range: DC to 10 kHz (-3 dB)
• Temperature range (sensor & cable): −35 to +180 °C
• 4-20 mA processed output option
• Built-in digital Modbus interface
• Robust and sealed design
• 5m or 10m total length systems

Components of a Smart Proximity System

• The Proximity System Probe (PSP): High-performance eddy-current sensor for precise, non-contact measurements in tough industrial environments
• The Proximity System Extension cable (PSE): Industrial-grade coaxial cable for easy disconnection and robust signal transmission
• The Digital Proximity Transmitter (DPT): Core processing unit, powers the probe and converts the measured signal into actionable data, offers both raw dynamic output and processed values via Modbus or optional 4–20 mA

All system elements are fully interchangeable, enabling quick on-site servicing and reducing downtime without compromising performance or signal integrity.
Understanding Signal Outputs

• Dynamic Voltage Output: Raw analog signal (8 mV/µm or 4 mV/µm) for commissioning, vibration analysis, or direct monitoring
• Modbus RTU (Digital Output): Real-time access to calculated values such as mean gap, peak, and peak-to-peak displacement
• 4–20 mA Processed Output (Optional): Digitally processed signal scaled to represent position or vibration amplitude

Integrated Proximity Probe (PPT-280)
The PPT-280 is a compact, all-in-one proximity probe designed for fast, straightforward installation without the need for external signal conditioners. It features integrated linearization electronics for excellent linearity and active temperature compensation. The integrated 750 kHz oscillator ensures a measurement with minimal magnetic run out effect. It delivers a direct voltage output proportional to the shaft’s position.

• One-component installation simplifies wiring and saves space—no external driver required
• Configurable setup using a field-adjustable kit (optional) for range and polarity tuning

PPT-280 Key Features

• Measurement ranges: 2mm (8mV/μm) and 4mm (4mV/μm)
• Frequency range: 0 to 1.2kHz
• Built-in linearization electronic & active temperature compensation
• Supplied with -24V or +24V depending on the configuration
• Optional: configuration kit and digital interface for setting and calibration
• 10m length

The PPT-280 is ideal for users seeking a compact, self-contained proximity probe that minimizes installation effort and component count.
Analog Proximity System (PPT-080/110)
The PPT-080/110 is a robust, API 670-compliant proximity probe system engineered for critical machinery protection in industrial and hazardous environments. Based on eddy-current technology, the system includes a probe, extension cable, and driver, delivering a raw voltage output (or optional 4–20 mA) directly proportional to shaft displacement. With optional ATEX, IECEx, and CSA certifications, this system is ideal for deployment in explosive atmospheres and regulated installations.

• Fully compliant with API 670 for protection of critical rotating equipment
• Available with ATEX and IECEx certifications for use in hazardous zones

PPT-080/110 Key Features

• Linear measurement ranges and sensitivity: 2mm and 4mm
• Certified for use in potentially explosive atmospheres
• 5m or 9m total length systems
• Loop powered transmitter (4-20mA)

The PPT-080/110 is the go-to solution for critical equipment protection in power plants, refineries, and heavy industry.
Available Models

• SPS: Measuring range 0.2mm to 2.2mm or 0.2mm to 4.2mm, Sensitivity 8mV/µm or 4mV/µm, Modbus interface
• PPT-280: Measuring range 0.2mm to 2.2mm or 0.2mm to 4.2mm, Sensitivity 8mV/µm or 4mV/µm, 10m integral cable
• PPT-080: Measuring range 0.25mm to 2.25mm, Sensitivity 7.87mV/µm, 8m or 4m extension cable
• PPT-110: Measuring range 0.4mm to 4.4mm, Sensitivity 3.94mV/µm, 8m or 4m extension cable
• PPT-990 configuration kit: Configuration kit for PPT-280

Applications

• Hydrogenerators
• Gas & steam turbines
• Pumps, fans & cooling towers

Advanced Analysis

• FFT – Frequency-Based Vibration Analysis: Converts the raw vibration signal into its frequency components, revealing mechanical faults like resonance, unbalance, or misalignment
• Orbit Plot – Shaft Vibration in the Radial Plane (X-Y): Visualizes the shaft's real-time motion in the horizontal plane using two orthogonal proximity probes
• Shaft Center Line – Radial Shaft Position Over Time (X-Y Plane): Shows the average position of the shaft within the bearing clearance, revealing how the shaft moves or drifts over time due to load changes, thermal effects, misalignment, or oil film behavior

Characteristics / Technical Specifications

• Non-contact eddy-current technology
• Measurement ranges: 0.2mm to 4.4mm depending on model
• Sensitivity: 3.94mV/µm to 8mV/µm depending on model
• Frequency range: DC to 10 kHz (SPS), 0 to 1.2kHz (PPT-280)
• Temperature range: −35 to +180 °C (SPS)
• Output options: Raw voltage, 4–20 mA, Modbus RTU
• API 670 compliance (PPT-080/110)
• ATEX, IECEx, and CSA certifications available (PPT-080/110)
• System lengths: 4m, 5m, 8m, 9m, or 10m depending on model
• Robust, sealed, and interchangeable components