The Measurable difference.

RPM & Angle Sensors


Optical tape sensor SE-TAPE-01 is a speed and angle sensor that uses a black/white tape attached to a rotating part. The reflection is converted into a TTL signal with a bandwidth 100 kHz. The sensor consists of a tiny electronics parts and a 5 m fiber optic cable terminated with a M6 screw. Therefore areas where space is very limited still can be reached conveniently.

Data sheet download


  • Impulse frequency: max. 100 000 pulses/s
  • Temperature range: -10 °C to +50 °C
  • Working area: 1 to 5 mm


Both sensors emit light which is reflected by an object and received by a photo transistor. The output of this sensor is an analog voltage signal.

When connected to an analog input of any DEWETRON system, the RPM and angle information is processed by software. You see the shape of the curve and can define the trigger level using angle mathematic calculations in the software.

Data sheet download


  • Impulse frequency: 10 to 15 000 pulses/s
  • Temperature range: -10 °C to +60 °C
  • Working area: 1 to 2 cm


-01 & -02

The difference between the Tacho-Probe-01 and -02 are the connectors on the 5 m cables. There is DB-9 connector on the probe-01 and BNC and Lemo connectors on the probe-02.


The DEWE-RIE (Rugged Industrial Encoder) works based on the transmission of light principle. Execution of this principle avoids attrition and malfunction.

The very rugged encoder is mounted between the engine and brake shaft. An infrared beam is emitted and received at the sensor unit. The customized marker disk (with slits) is mounted in-between the sensors gate. When the slits interrupt the infrared beam the receiver transforms the light to voltage.

DEWE-RIE offers TTL signal output and can be connected directly to any combustion analyzer or torsional and rotational vibration analysis system from DEWETRON.

Data sheet download


  • Impulse frequency: max. 125 000 pulses/s
  • Temperature range: -10 °C to +60 °C
  • Up to 10 000 rpm
  • Optional magnetic “quick mounting kit” for test installation



Two types are available by default (other diameters on request):

  • 360 slits = 1° resolution (outer diameter 120 mm)
  • 720 slits = 0.5° resolution (outer diameter 230 mm)

Just the Basics

RPM and Angle sensors are critical components in today’s industrial equipment and machinery. Specifically, the position information collected by the sensor is used during research and development, quality assurance and to prevent accidents in the industrial environment.  Similarly, ships and aircraft rely on rotary angle sensors to remain balanced, upright and level. Accordingly,the versatility of the sensor extends into the automotive and mining industries.

Angles Sensors (also called rotary angle sensors) and RPM sensors convert the motion or angular position of any rotating machine part, axle or shaft into digital or analog output signals that can then be measured and analyzed with data acquisition hardware and software.


DEWETRON’s Connection

DEWETRON precision data acquisition and recording instruments support several sensors required for torsional and rotational vibration analysis.

Firstly, the most basic and universal rotational sensor is Black and White optical sensor tape. To explain, when this tape is adhered to a rotating part reflections are created during rotation and converted into a TTL signal with a 100 kHz bandwidth. For example, with only 5m of fiber optic cable terminating with a M6 screw and minute electronics, the sensor tape is perfect for very small or limited spaces and impulses to 100,000 per second.

Additionally, Tacho probes, sensors emitting light that is reflected from a rotating part and received by a photo sensor, can be connected to any DEWETRON instrument through the analog input. When connected to the instrument, the analog voltage signal created by the sensor is processed through proprietary software that identifies the RPM and angle information and presents that data in the form of a curve.  The trigger level is then defined in the prepared angle calculation of the software.

Our tacho probes have 5 m cables and are available with DB-9, BNC and Lemo connectors.

Finally, we offer an industrial rotary angle encoder that uses the transmission of light to avoid attrition and malfunction. When the grooves on a customized marker disk interrupt an infrared beam (emitted from the encoder mounted between an engine and brake shaft), the receiver transforms the light to voltage. Voltage measurements are recorded with our data acquisition instruments.

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