A Quad B refers to the set of output quadrature signals from an incremental quadrature encoder to indicate speed and direction, including complements: A, A NOT, B, B NOT (, , , ). Most Avtron encoders offer A Quad B output at no extra cost.  For more information on quadrature- Wikipedia: http://en.wikipedia.org/wiki/Quadrature_phase

ATEX is a directive used worldwide for equipment, including encoders, to be used around or in explosive atmospheres. ATEX certified equipment is NOT necessarily interchangeable with US-based UL Class/Division or Class/Zone rated equipment, nor IECEx rated equipment. ATEX is an alternative and different system. Review our full line of Avtron Explosion Protected, ATEX certified encoders, including M6, M6C and XR models.

Motor shaft movement in or out, relative to the ends of the motor. Often motors that use roller or sleeve bearing construction have more axial shaft movement. Most Avtron modular encoders tolerate +/- 0.050" of axial movement maximum. Use hollow shaft encoders for high axial movement motor styles, such as MD motors. Most competitors’ modular encoders tolerate much less axial movement than Avtron products.

These encoders use the bearings of the motor or machine, eliminating a huge source of failure in encoders.  Also known as modular and sandwich encoders.

Also known as contaminants, such as water, dirt, dust, oil, and other compounds which enter an encoder through seal failure and can cause optical errors. If the contamination is abrasive, it can also cause bearing failures in the encoder. Modular encoders are very resistant to contamination as they use magnetoresistive sensors and have no bearings.

A device which indicates position and speed via a set of digital outputs. Incremental encoders output quadrature (A Quad B) signals, and may add a marker pulse once per revolution.  Absolute encoders typically indicate position via a digital message, a set of parallel outputs, or analog values.

Also known as Flameproof, explosion protected equipment has additional protection/safety enhancements for use in explosive atmospheres. Explosion Protected devices maybe placed directly into hazardous areas within their nameplate rating. No additional equipment is required if installation instructions are followed properly. By comparison, Intrinsically Safe devices may require the use of additional, external protection/current limiting devices outside of the hazardous area. Avtron offers hollow shaft M6C Explosion Protected encoders.

Also known as Explosion Proof, flameproof encoders have additional protection/safety enhancements for use in explosive atmospheres. Flameproof encoders maybe placed directly into hazardous areas within their nameplate rating. No additional equipment is required if installation instructions are followed properly. By comparison,
Intrinsically Safe encoders may require the use of additional, external protection/current limiting devices outside of the hazardous area. Avtron offers hollow shaft M6C Flameproof encoders.

IECEx is a directive used worldwide for equipment, including encoders, to be used around or in explosive atmospheres. IECEx certified equipment is NOT necessarily interchangeable with US-based UL Class/Division rated equipment, or ATEX rated equipment. IECEx is an alternative and different system. Avtron offers a full famliy of Explosion Protected, IECEx certified XR encoders, and M6C is also IECEx certified.

An encoder that produces pulses in proportion to distance moved or rotated. Incremental encoders can also have a marker pulse Z, Z NOT (, ) once per revolution to provide a position reference. Avtron produces a full range of incremental rotary encoders.

Is a system designed to improve equipment safety by limiting spark energy values in equipment used in hazardous areas.  Intrinsic Safety is a different system of protection than Explosion Proof or Flameproof.  Many Explosion Proof and Flameproof encoders can be replaced with Intrinsically Safe encoders, provided the installation instructions are followed correctly and the system is compliant with the approved installation drawing.  Intrinsically safe Avtron XR encoders are available in Level 1 protection and Level 2 protection. 

Infra-Red Light Emitting Diode is the light source for an optical encoder.

Magnetic and magnetoresistive encoders typically use a magnetized rotor with north and south poles lined up around the perimeter of the disk. A magnetoresistive sensor detects the transitions, and these are the counts or pulses generated by the encoder. Magnetic encoders withstand dirt, dust, water, and temperature changes far better than optical encoders.

A magnetized disk with multiple north and south poles lined up around the perimeter of the disk. A magnetoresistive sensor detects the transitions and generates the pulses generated by the magnetic encoder.

A sensor that detects the magnetic poles on an encoder's magnetic rotor and transforms them into pulses. Avtron magnetoresistive (MR) sensors use advanced technology to reject external magnetic signals such as brake solenoids and motor magnetic fields. MR sensors enable Avtron magnetic encoders to ignore dirt, oil, water, and other contaminants.

The Marker Pulse occurs once per revolution. The purpose of the marker pulse is to provide a repeatable home position location for positioning applications. The marker pulse is often abbreviated as "ØZ" or "Z" in the USA and "C" or "N" in Europe.

Modular Encoders mount to a machined C-face or flange adapter on the motor (drive or non-drive end). Modular encoders consist of a rotor that mounts on the shaft, and a stator that bolts to the motor frame. Modular encoders are very rugged, and Avtron encoders feature Wide-Gap sensors to avoid complex shimming or fitting to the motor. Modular C-face encoders are typically used on DC motors; but some AC motors, such as Rockwell’s RPM III AC and Marathon’s Blue and Black Max motors, have C-faces standard on the non-drive end for mounting an encoder.

The high-speed switching of variable frequency drives that is used to control the speed of motors often produces current which flows from the motor shaft to ground, or from end-to-end of the motor.  These current are highly destructive to both motor and encoder bearings.  Preventing shaft current damage is essential.  Most Avtron hollow shaft encoders include features to prevent motor shaft current damage.  For more information:  http://www.avtronencoders.com/knowledge-base/eliminating-damage-from-motor-shaft-currents-through-tachometers-and-encoders or visit Wikipedia:  http://en.wikipedia.org/wiki/Shaft_voltage

An Optical Disk is typically a glass, metal, or plastic disk with fine lines or slots etched around the perimeter that interrupt the beam of light from the light source to an optical sensor. Optical disks can be quite fragile. Avtron uses only shatterproof optical disks with Wide-Gap technology.

An Optical Encoder typically uses a light source shining through, or reflecting off, an optical disk with lines or slots that interrupt the beam of light to an optical sensor. Electronics count the interruptions of the beam and generate the encoder’s output pulses.

Optical Sensors are typically phototransistors or other light sensors which sense the light emitted by the light source, as interrupted by, or passed through, the optical disk.

Pulses Per Revolution. Most Avtron encoders output quadrature pulses, with four times as many lines as pulses. Often lines can be counted in the drive/speed controller for higher resolution applications.

Pulses are also known as counts and are the low voltage output transitions which indicate movement of the encoder. Encoders are rated by resolution or PPR (pulses per revolution). Pulses are not the same as lines.

A rotary encoder provides position and/or speed feedback information about a rotating shaft.  Rotary encoders may be hollow shaft, no-bearing modular, coupled solid shaft style.  They may provide absolute positioning information, or incremental velocity feedback. Avtron rotary encoders are designed and built to be far more reliable than ordinary rotary encoders. Avtron encoder white papers on our blog provide more details of how and why Avtron rotary encoders are more reliable.

The disk-shaped portion of the modular encoder that is mounted on the motor shaft. Avtron modular encoders use magnetic rotors.

UL Listed Avtron encoders can be directly applied to any hazardous duty application which requires Class and Division, Class and Zone or AEX certification.  Note that UL Listing is a different system than ATEX or IECEx.  Ensure the model you select has the UL listing which meets the application requirements.