Novotechnik Linear Position Transducers Compared: Which Series to Specify

The Novotechnik linear position transducer range covers four distinct measurement technologies across more than a dozen mechanical formats. Approached as a catalogue it is bewildering. Approached as three questions it resolves quickly.

The questions are: how is it mounted, how long does it have to last, and does anything need to be inside a cylinder.

The four technologies

Potentiometric — a precision conductive plastic track with a wiper. Simple, absolute, direct DC output, no conditioning electronics, lowest installed cost. The wiper contacts the track, so there is a wear mechanism, though Novotechnik designs use a decoupled wiper tap and pendular fixed slide bearing specifically to give stick-slip-free movement and long life.

NOVOSTRICTIVE (magnetostrictive) — non-contacting. A magnet moves along a waveguide and position is derived from the timing of a returned pulse. No wear in the measuring path, long strokes available, and it can be built as a rod for installation inside a hydraulic cylinder.

NOVOPAD (inductive) — non-contacting inductive measurement in a compact profile. A wear-free alternative in a smaller package than magnetostrictive.

Integrated signal processing types — the TE1 family, which includes signal processing in the transducer and can be replaced without recalibration. That last property is worth noting for maintained plant: swapping the unit does not mean a commissioning exercise.

Question one: how does it mount

This narrows the field faster than anything else.

Rod style, actuated by a moving machine element

• TEX rod type — potentiometric, pendular fixed slide bearing, decoupled wiper, long life
• TX2 — potentiometric with a double-supported actuating rod, high adjustment speed. Available with pivot head mounting or mounting clamp.
• LWH and LWG — potentiometric, the general-purpose workhorses of the range
• LWX-003 and LWX-004 — the LWX-004 with a shaft-protected design for dirtier positions

Side actuated

• TLH — potentiometric, side actuated, IP40 to IP54, rated from below minus 30 to above plus 100 degrees Celsius

Spring return, where the machine pushes but does not pull

• TR and TRS with return spring, TEX with return spring, TE1 with return spring, LS1 with return spring

A return spring matters more than it sounds. If the actuating element only pushes the rod and relies on it following back, the spring is doing the measurement on the return stroke — and if it is absent or too weak for the speed, the reading lags.

Profile designs

• TP1 — NOVOSTRICTIVE magnetostrictive in a robust profile, non-contacting
• LS1 — NOVOPAD inductive, compact profile, double-sided supported actuating rod

Inside a hydraulic cylinder

• TH1 — NOVOSTRICTIVE rod style, designed for integration into cylinders

Sensor kits for integration into your own housing

• PTX — potentiometric sensor kit, for OEMs building the transducer into their own mechanics

Question two: how many cycles

This decides contacting against non-contacting.

For machine positioning, valve feedback, press setup and general industrial measurement at moderate cycle rates, potentiometric is entirely adequate and considerably cheaper installed. The objection people raise — that the wiper wears — is usually based on experience with wirewound potentiometers rather than conductive plastic elements with decoupled wipers.

For continuous high-cycle duty, for washdown environments, or where a failure is expensive enough that the wear mechanism is unacceptable in principle, specify NOVOSTRICTIVE or NOVOPAD. The cost difference buys the removal of the only wear path.

Question three: cylinder integration

If the measurement has to happen inside a hydraulic cylinder, the answer is TH1 and the other questions become secondary. A rod-style magnetostrictive transducer installed in a gun-drilled cylinder rod gives you position with nothing exposed to the outside world at all — no rod to be damaged, no seal to fail, no alignment to lose.

This is the right answer for mobile machinery, presses and any cylinder in a position where an external transducer would be destroyed.

Interfaces

Most of the range offers ratiometric or analogue output as standard. TH1, TP1 and TM1 also offer CANopen and IO-Link, which is worth knowing if the machine architecture is bus-based — see CANopen position sensors.

A quick way through

1. Inside a cylinder? TH1.
2. OEM integration into your own housing? PTX.
3. High cycles, wet, or wear unacceptable? TP1 or LS1.
4. Needs to be replaceable without recalibration? TE1.
5. Everything else — LWH, TEX or TX2 depending on mounting, with a return spring variant if the actuator only pushes.

What to send us

Stroke length, mounting arrangement, whether the actuator pushes only or both ways, expected cycles per day, required accuracy as a number, output needed, protection rating, and temperature range. A sketch of the mechanical arrangement is worth more than any of them individually. Our note on selecting a linear position transducer covers the mechanical decisions in more depth.