Non-Contact Rotary Sensors Manufacturers online

Non-contact angle sensors are electronic devices that detect the rotational position (angle) of an axis or object without mechanical contact between the sensor and the object being measured.

This means that there is no physical connection between the sensor and the rotating part, which offers many advantages such as less wear and tear, longer service life and greater reliability.

Operating principles of angle sensors

Depending on the technology, non-contact angle sensors work with different physical effects. The most common methods are:

1. Magnetic-inductive sensors

• A magnet is attached to the rotating object.
• The sensor contains a Hall or GMR (Giant Magnetoresistance) element that measures the change in the magnetic field during rotation.
• The measured change in the magnetic field is converted into an electrical angle.

Advantages

• Robust design
• Insensitive to dust, oil and water

2. Optical sensors

• Here, a light beam (usually infrared) is directed through a coded disc.
• This disc rotates and creates light and shadow patterns due to its structure.
• A detector recognises these patterns and derives the position from them.

Advantages

• Very high accuracy
• Resolution in the microrad (a unit of angular measurement) range possible

Disadvantage

• Sensitive to contamination and mechanical influences

3. Capacitive sensors

• Detect changes in the capacitance between two electrodes, which change during rotation.
• Ideal for smaller angle ranges.

Advantages

• Very sensitive
• Small design possible

4. Magnetostrictive sensors

• Use the property of magnetostrictive materials to change their magnetic properties when deformed.
• Rare for angle sensors, more common for linear measurement, but possible.

Areas of application

Non-contact angle sensors are used in many industries, for example:

• Automotive industry: Steering angle, throttle valve position, pedal position
• Robotics: joint positions, precision movements
• Industrial automation: machine control, position feedback
• Medical technology: joint movements in prostheses or rehabilitation devices
• Aerospace: flap control, instrument adjustment

Advantages of contactless angle sensors

• No wear, as there is no friction
• Durable and low maintenance
• High reliability, even in harsh environments
• Precise measurement possible, depending on the technology

Disadvantages

• Costs can be higher than for mechanical potentiometers
• Magnetic interference can be problematic with magnetic sensors (shielding measures necessary)
• Mounting precision important to obtain accurate results

Non-contact angle sensors and other products are available from the manufacturers listed on Exportpages.