Omnipolar Hall Effect Tachometers for Speed Measurement

An omnipolar Hall-effect tachometer is a single-channel speed sensor designed to detect magnetic fields with full-polarity response, allowing it to respond reliably to either north or south magnetic poles. This characteristic simplifies installation and alignment, as the sensor does not require strict magnetic polarity orientation. The sensor outputs clean voltage pulse signals with strong anti-interference capability, making it suitable for accurate rotational speed measurement in electrically noisy industrial environments.

Built with an integrated stainless-steel housing, the omnipolar Hall-effect tachometer provides durable, non-contact speed measurement for gears, shafts, and rotating components. Because it operates without physical contact, the sensor avoids mechanical wear, ensuring maintenance-free operation and long service life even under continuous use. Threaded installation options and customizable electrical specifications further enhance its adaptability for harsh and space-constrained installations.

Operating Principle

The tachometer operates based on the Hall effect, where a voltage is generated when a magnetic field passes through a semiconductor element. Each time a magnetic target—such as a magnet embedded in a rotating shaft or gear—passes the sensing face, the sensor produces a corresponding electrical pulse. The frequency of these pulses is directly proportional to the rotational speed of the target, allowing accurate speed or RPM calculation.

Because the sensor is omnipolar, it detects magnetic field changes regardless of polarity, improving signal reliability in applications with varying magnetic orientations or installation constraints.

Key Characteristics

The omnipolar Hall-effect tachometer offers a wide operating frequency range from 0.1 Hz to 10 kHz, enabling precise measurement of both very slow rotation and high-speed motion. A working air gap of up to 20 mm provides installation flexibility and tolerance for mechanical runout or vibration.

Two representative models support different system requirements:

• DT8H001-N

  • Operating frequency: 0.1 Hz–10 kHz

  • Working air gap: 0.5–20 mm

  • Power supply: DC 5 V to 28 V

  • Size: Ø10 × 60 mm

• DT8H002

  • Operating frequency: 0.1 Hz–10 kHz

  • Working air gap: 0.5–20 mm

  • Power supply: DC 3.3 V

  • Size: 27 × 8 × 8 mm

These options allow engineers to select the most suitable form factor and voltage level for their application.

Typical Applications

Omnipolar Hall-effect tachometers are widely used in:

• Industrial machinery speed monitoring, including motors, conveyors, and gear systems

• Automotive and transportation systems, for wheel speed and rotational feedback

• Automation and control systems, where reliable pulse-based speed signals are required

• Harsh industrial environments, where dust, oil, vibration, and temperature variation are present

System Integration

The sensor integrates seamlessly with Dynatronic data acquisition and monitoring systems. When combined with controllers, counters, or DAQ hardware, the pulse output enables precise speed analysis, synchronization, and condition monitoring alongside other parameters such as vibration, torque, or temperature.

Reliable Non-Contact Speed Measurement

By combining omnipolar magnetic detection, rugged stainless-steel construction, and flexible electrical options, the omnipolar Hall-effect tachometer delivers reliable speed measurement with minimal installation effort. It is a practical and dependable solution for engineers who require accurate rotational feedback in demanding industrial applications.