RHEINTACHO FE Rotational Speed Sensor Does It All

The three musketeers of the sensor world: installation-compatible 1-channel, 2-channel, PWM

by Melanie Nubling | Thursday 12 January 2017

The RHEINTACHO FE rotational speed sensor provides you with today’s most frequently used signal forms: 1-channel, 2-channel and PWM signal output. Three different electronic versions, each in installation-compatible, highly compact housings.

It doesn’t matter whether you’re a manufacturer who equips their hydraulic units with rotational speed measurement devices or whether you’re a user who buys such units from highly regarded suppliers. You know the question. From the user’s perspective it goes: “Does the standard integrated solution for measuring rotational speed fit?” All too frequently, you have to answer: “No”.

Now let us step into the shoes of the hydraulics supplier and ask the same question: “Does your standard-use rotational speed measurement device fit your customer’s demands precisely?” Probably, the answer here is all too often also: “No”.

As competent partners, you do of course find a solution. No doubt a well-functioning custom solution. But unfortunately, it comes with all the mixed blessings that custom solutions imply. We all know the indisputable advantages of the typically German enthusiasm for custom solutions that are usually nice and smart. So allow us to mention just a couple of the disadvantages: project-related, unplanned development expenditure; no amortisation with larger numbers of items; additional testing and qualification expenditure; additional documentation expenditure; defect potential when upgrading the system; defect potential when servicing ‘in the field’.

At this point, the engineers at RHEINTACHO would like to cry out: “It doesn’t have to be like this!”

For decades, RHEINTACHO has been a successful supplier of rotational speed counting solutions for hydraulic drive units and has participated in and helped to shape many stages of development in this market. During this time, the scenario sketched out above has also come to pass at RHEINTACHO all too often.

Therefore, one of the main targets in the development of the new sensor range right from the first analyses and feasibility studies was to take into consideration the various electronic variants typically found on the market and to allow these to influence the product development process at an early stage.

And it turns out it paid off. The RHEINTACHO FE range offers three (3) different electronic versions (1-channel, 2-channel, PWM), two (2) different immersion depths (18.4 mm and 32 mm) and a variety of different cable lengths and types of plugs (on the cable).

All sensors in this range are built to protection classes IP6K9K and IP67.
The 1-channel version is the ideal choice if the needs are limited to the measurement of rotational speed. Carefully selected components guarantee highly tolerant contact behaviour with respect to all types of target geometries and air gaps. The output signal here is a square wave, the amplitude of which is independent of the rotational speed. In this way, stable signals are achieved even with slow rotational speeds.

With its two phase-shifted square wave signals, the 2-channel solution offers the same advantages as mentioned above. However, with its two offset signals, you have the additional possibility of identifying the direction of rotation.
In contrast to the two variants described above (voltage signal), the 2-channel construction with pulse-width modulated signal (PWM) works using a current signal, with information regarding the rotational direction transmitted via the varying length of the pulses. In this way, this sensor also produces a signal with constant amplitude, independent of the rotational speed. This sensor boasts not only the ability to identify the rotational direction; it can also carry out other diagnostic functions such as the identification of idle status, a critical air gap and critical installation position.

The advantages of the RHEINTACHO FE concept are easy to see: a sensor range for your hydraulic unit is specified and released. The mechanical interfaces are identical, regardless of which signal you or your users decide on. You choose the appropriate rotational speed sensor based precisely on the application’s specific requirements.

Save your time and expertise regarding custom solutions for the situations where there really is no standard solution available!


Bill Buhler
+44 113 287 4411

Thursday 12 January 2017 / file under Machinery | Engineering