IncOder™ Inductive Angle Encoders

Non-contact, inductive angle encoders for high-precision, reliable measurement in harsh environments.

  • Non-contact technology for high reliability in extreme environments
  • Proven in aerospace, defence, medical & industrial applications
  • Over 400 million product configuration options available
inductive encoder

Robust Angular Position Measurement for Extreme Environments

Zettlex IncOders are non-contact devices for precision angle measurement. They work like a transformer, using an inductive technique. IncOders may be considered as an inductive angle encoder.

IncOders are ideally suited to harsh environments – where potentiometers, optical or capacitive devices may prove unreliable.


High-reliability Inductive Angle Encoder Technology

IncOders have 2 main parts – a Stator and a Rotor – each shaped like a flat ring. The large bore makes it easy to accommodate through-shafts, slip-rings, optical-fibres, pipes or cables.

The Stator is powered and the Rotor is passive. The Stator contains the electronics to receive power and generate an output signal. The output signal from the Stator shows the true absolute angular position of the Rotor relative to the Stator without the need of any motion.

Simple Installation; ‘Fit and Forget’ Technology

IncOder inductive angle encoders do not require compliant or special couplings and the Rotor & Stator can simply be screwed to the host product. Precise mechanical mounting is not required and there are no bearings.

Whereas optical or capacitive angle encoders can be unreliable in harsh conditions – notably with condensation or dust – Zettlex angle encoders are generally unaffected by foreign matter and IP67 rated versions are available. Unlike capacitive devices, there is no need to earth the Rotor or Stator. Robust, hard-anodized aluminium alloy housings and monolithic constructions are used throughout.

There are no contacting, delicate or wearing parts, so there is no need for periodic replacement, service or maintenance. In other words, IncOder angle encoders are true ‘fit and forget’ devices.


Inductive Angle Encoder Specifications / Options

Mechanical Formats
12 mechanical formats featuring screw or servo clamp Stators with screw format, set screw, shaft clamp and plain Rotors, duplex Stators and Rotors.
Packaged formats include servo clamp or screw flange.
IncOder Size Options (Stated as Outer Diameter)
37, 58, 75, 90, 100, 125, 150, 175, 200, 225, 250, 300, 325, 379, 429 & 595mm
Resolution Options
10 to 22bits & user selectable pulses per rev for A/B pulse outputs
Connection Options
Axial connector, radial flexi (with or without connector) & integral axial cable
Voltage Options
5, 12 or 24VDC
Communication Interface Options
Analogue voltage
A/B/Z pulses
Extended Range Options
(Not Typically Required for Most Application Types)

Ultra high shock & vibration
Cold temperature option to -60°Celsisus
High temperature option to +105°Celsisus
Leaded solder
Burn in prior to acceptance testing
Surtec650 surface finishes
Prolonged immersion, salt spray or extreme dust conditions
High Pressure


  • Rotary joints & gimbals
  • Actuator servos & motor encoders
  • Electro-optical & infra-red camera systems
  • Heliostats & solar equipment
  • Robotic arms & CNC machine tools
  • Test & calibration equipment
  • Light & heavy calibre weapons systems
  • Targeting systems & range finders
  • Antenna pointing devices & telescopes
  • Packaging & laboratory automation
  • Medical scanners & surgical equipment
  • Cranes & telescopic manipulators
Inductive encoder for marine
Medical Equipment Angle encoder

We have a comprehensive library of 3D CAD files available to assist designers in the integration of our inductive angle encoders. Click the button below to view available files, or contact us if you’re looking for something specific that is not listed.

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Over 400 million angle encoder variations. Which one suits your project?


37 – 58mm

Midi IncOder Angle Encoder

75 – 300mm

Maxi IncOder Angle Encoder

325 – 595mm


Have a question about the IncOder product range? Here we answer a selection of frequently asked questions.

If your question doesn’t appear, please get in touch with one of our experts.

IncOders work in a similar way to brushless resolvers and rotary variable transformers.  The IncOder Stator receives a DC power source and produces a low power AC electromagnetic field between the Stator & Rotor. This field is modified as the Rotor rotates.  The field is sensed by the Stator and the rotation angle output as an analogue or digital signal.  Unlike resolvers, IncOders use laminar circuits rather than wound wire spools. The patented technology enables IncOder’s compact form, low mass, low inertia and high accuracy without high precision installation.

Yes. Measurements will be the same before and after power interruption. No motion is needed at start up.

Yes. If BIT shows an internal error then an error signal is generated. The BITs include continuity/damage, presence of Rotor, in-range Rotor, gross electromagnetic malfunction, window watchdog timer, power on reset, power brownout reset, timeouts for clock input, read/write and internal flash data memory value checks.

Measurement performance is unaffected by humidity, condensation, dirt, dust, oil, mud or sand. All IncOders will survive temporary immersion to depths of 1m in salt or fresh water. Where frequent exposure to liquids, or immersion, is part of the operating environment, units with connections type AFL or VFL should be used.

No. Magnets produce DC fields.  IncOder’s operation is based on the detection of AC electro-magnetic fields at a highly specific frequency.

Use this document as a basis and specify any differences. Preferably, a standard outer diameter ‘A’ dimension (i.e. 37, 58, 75, 100, 125 mm etc.) and a proportionate inner diameter should be used. This enables us to use regular sensor components with analternative mechanical format.

Resolution, repeatability & accuracy (linearity) will be as specified, provided Rotor concentricity is within specified limits. One might expect accuracy to degrade significantly with concentricity, but IncOders use the full faces of Rotor & Stator, so errors are nulled by diametrically opposing factors. This is different to other encoder technologies – notably optical or capacitive devices – where performance depends on tightly controlled concentricity.

Yes. Many IncOders are used near powerful sources of electromagnetic noise such as motors or transformers. IncOder’s aluminium housing produces a Faraday cage effect around the internal electronics and the technology is designed so that incoming, far-field radiation is self cancelling or filtered out.

The longer the transmission distance (Cable Length), the slower the recommended Baud Rate. This table shows recommended Baud Rates vs. Cable Length.

Cable Length (m)<30<60<120<250
Baud Rate<400 kHz<300 kHz<200 kHz<100 kHz

Operating temperature limits are set by some of IncOder’s electronic parts rather than the basic technique. Standard IncOders are rated -40 or 85oC operation and with a cold option (Product Options 12VCT & 24VCT) for -60oC operation. IncOders can be used outside these limits following qualification by the user. At temperatures >85oC the duration of any elevated temperature should be minimized. At temperatures at or below the stated lower limit, it is recommended to leave the unit powered or allow an extended powered period (>1 minute) before operation.

Yes. Use AFL or VFL cable connections or provide a mechanical seal around the connector. Some AFL or VFL connections are rated for submersion at <100m, however, some applications are successfully using such devices for prolonged submersion in water or mineral oil at >100m depth, without modification. If application requirements are for prolonged and>100m submersion, this should be qualified by the user. Contact us for further information.

Not usually. IncOders are exempt from Annex I to Council Regulation (EC) No. 428/2009, as amended [EU Dual-Use List] and only require an export license if the diameter is greater than or equal to 1000mm or accuracy is <1arc-second. No standard products are in this class.

Calibration is only relevant for some ultra high accuracy applications such as astronomical telescopes. Readings from an IncOder are stored and compared to a reference in a look-up table in the host system. Such an arrangement will negate any inaccuracy due to inherent non-linearity or installation tolerances. Resolution & repeatability are unaffected by calibration.

    IncOder Inductive Angle Encoder Enquiry

    If you’d like to know more about IncOder angle encoder technology, would like to discuss your application requirements or would like to place an order, please complete the form below.

    Local Contacts

    Global Head Office

    Faraday House, 40 Barrington Road, Foxton, Cambridge, CB22 6SL, UK
    Tel: +44 (0) 1223 874444

    USA East Office

    125 Middlesex Turnpike, Bedford, MA 01730, USA
    Tel: +1 781 266 5200

    Germany Office

    Parkring 57 – 59, 85748 Garching bei München, Germany
    Tel: +49 (0) 89 31707137

    Operations Centre

    Newton Court, Newton, Cambridge, CB22 7ZE, UK
    Tel: +44 (0) 1223 874444

    USA West Office

    3900 Atherton Road, Suite 110, Rocklin, California 95765, USA
    Tel: +1 916 652 3118


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