Epro PR9376/20 Hall-Effect Speed Sensor

Overview

The EPRO PR9376/20 is a non-contact Hall-effect speed and proximity sensor developed for rotational monitoring in turbomachinery systems. It is widely applied on turbines, compressors, pumps, and gear-driven equipment where reliable pulse generation from ferromagnetic targets is required for speed control and protection functions.

The device converts changes in magnetic flux caused by passing gear teeth or shaft features into electrical pulse signals, enabling accurate speed measurement even in demanding operating environments.

Operating Principle

This sensor uses a Hall-effect semiconductor element to detect variations in magnetic fields. When a ferromagnetic target passes through the sensing zone, the internal circuit switches rapidly, producing a clean digital output signal suitable for speed counting and overspeed monitoring systems.

Technical Specifications

• Sensing technology: Hall-effect magnetic detection

• Detection method: Non-contact pulse generation from rotating ferromagnetic targets

• Compatible targets: Steel, soft iron, gear teeth, shaft keyways (non-stainless materials only)

• Output signal: Square wave pulse proportional to target passage

• Output levels: High >10 V / Low <1 V (typical 12 VDC, 100 kΩ load)

• Supply voltage: 10–30 VDC, approx. 25 mA maximum (variant dependent)

• Switching response time: 1 µs

• Frequency capability:

• Standard configuration: up to 12 kHz

• Extended variants: up to 50 kHz depending on system design

• Air gap requirement: 1.0 mm (Module 1), 1.5 mm (Module ≥2)

• Operating temperature: -25 °C to +100 °C

• Storage temperature: -40 °C to +100 °C

• Protection rating: IP65 to IP67 depending on version

• Housing: Stainless steel with PTFE-insulated cable

• Sensor diameter: 14 mm

• Overall length: approximately 160 mm

• Weight: 210 g

• Compliance: CE (2014/30/EU, 2014/35/EU), RoHS compliant

Key Characteristics

• Fully non-contact operation eliminates mechanical wear

• Stable pulse output for speed and position monitoring systems

• High switching frequency suitable for fast rotating machinery

• Stainless steel housing designed for harsh industrial environments

• Wide temperature tolerance for turbine and compressor applications

• High ingress protection against dust, oil mist, and moisture

Installation Guidelines

Proper alignment between the sensor face and target wheel is critical for stable signal generation. Recommended air gap is 1.0–1.5 mm depending on gear module size. Installation deviation may result in unstable pulse output or reduced signal amplitude.

Shielded cables are recommended in electrically noisy environments to maintain signal integrity and reduce interference.

Application Areas

• Steam and gas turbine speed monitoring

• Compressor shaft speed measurement

• Industrial pump rotational monitoring

• Gearbox speed and position detection

• Overspeed protection systems

• Industrial condition monitoring setups

FAQ

Q: Does the PR9376/20 work with stainless steel targets?
A: No. It requires ferromagnetic materials such as carbon steel or soft iron.

Q: Can it detect very low rotational speeds?
A: Yes, but performance depends on target geometry and installation accuracy.

Q: What is the impact of incorrect air gap adjustment?
A: It may lead to weak signals, jitter, or missed pulses.